An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
Measurement of the intensity and quality of fluorescence.
A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.
Measurement of the polarization of fluorescent light from solutions or microscopic specimens. It is used to provide information concerning molecular size, shape, and conformation, molecular anisotropy, electronic energy transfer, molecular interaction, including dye and coenzyme binding, and the antigen-antibody reaction.
A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
A type of FLUORESCENCE SPECTROSCOPY using two FLUORESCENT DYES with overlapping emission and absorption spectra, which is used to indicate proximity of labeled molecules. This technique is useful for studying interactions of molecules and PROTEIN FOLDING.
Chromatographic techniques in which the mobile phase is a liquid.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (keV) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. Digital imaging can be generated from the secondary ion beams and their intensity can be measured. Ionic images can be correlated with images from light or other microscopy providing useful tools in the study of molecular and drug actions.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A method used to study the lateral movement of MEMBRANE PROTEINS and LIPIDS. A small area of a cell membrane is bleached by laser light and the amount of time necessary for unbleached fluorescent marker-tagged proteins to diffuse back into the bleached site is a measurement of the cell membrane's fluidity. The diffusion coefficient of a protein or lipid in the membrane can be calculated from the data. (From Segen, Current Med Talk, 1995).
The systematic study of the complete complement of proteins (PROTEOME) of organisms.
Fluorescence microscopy utilizing multiple low-energy photons to produce the excitation event of the fluorophore. Multiphoton microscopes have a simplified optical path in the emission side due to the lack of an emission pinhole, which is necessary with normal confocal microscopes. Ultimately this allows spatial isolation of the excitation event, enabling deeper imaging into optically thick tissue, while restricting photobleaching and phototoxicity to the area being imaged.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.
The rate dynamics in chemical or physical systems.
An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
The protein complement of an organism coded for by its genome.
The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
A family of 3,6-di(substituted-amino)-9-benzoate derivatives of xanthene that are used as dyes and as indicators for various metals; also used as fluorescent tracers in histochemistry.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
An analytical method for detecting and measuring FLUORESCENCE in compounds or targets such as cells, proteins, or nucleotides, or targets previously labeled with FLUORESCENCE AGENTS.
Compounds that contain three methine groups. They are frequently used as cationic dyes used for differential staining of biological materials.
The use of light interaction (scattering, absorption, and fluorescence) with biological tissue to obtain morphologically based information. It includes measuring inherent tissue optical properties such as scattering, absorption, and autofluorescence; or optical properties of exogenous targeted fluorescent molecular probes such as those used in optical MOLECULAR IMAGING, or nontargeted optical CONTRAST AGENTS.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)
A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Electrophoresis in which a second perpendicular electrophoretic transport is performed on the separate components resulting from the first electrophoresis. This technique is usually performed on polyacrylamide gels.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Fluoroimmunoassay where detection of the hapten-antibody reaction is based on measurement of the increased polarization of fluorescence-labeled hapten when it is combined with antibody. The assay is very useful for the measurement of small haptenic antigens such as drugs at low concentrations.
Elements of limited time intervals, contributing to particular results or situations.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.
The spectrometric analysis of fluorescent X-RAYS, i.e. X-rays emitted after bombarding matter with high energy particles such as PROTONS; ELECTRONS; or higher energy X-rays. Identification of ELEMENTS by this technique is based on the specific type of X-rays that are emitted which are characteristic of the specific elements in the material being analyzed. The characteristic X-rays are distinguished and/or quantified by either wavelength dispersive or energy dispersive methods.
Light-induced change in a chromophore, resulting in the loss of its absorption of light of a particular wave length. The photon energy causes a conformational change in the photoreceptor proteins affecting PHOTOTRANSDUCTION. This occurs naturally in the retina (ADAPTATION, OCULAR) on long exposure to bright light. Photobleaching presents problems when occurring in PHOTODYNAMIC THERAPY, and in FLUORESCENCE MICROSCOPY. On the other hand, this phenomenon is exploited in the technique, FLUORESCENCE RECOVERY AFTER PHOTOBLEACHING, allowing measurement of the movements of proteins and LIPIDS in the CELL MEMBRANE.
Discrete concentrations of energy, apparently massless elementary particles, that move at the speed of light. They are the unit or quantum of electromagnetic radiation. Photons are emitted when electrons move from one energy state to another. (From Hawley's Condensed Chemical Dictionary, 11th ed)
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.
Spectrophotometric techniques by which the absorption or emmision spectra of radiation from atoms are produced and analyzed.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
A class of organic compounds which contain an anilino (phenylamino) group linked to a salt or ester of naphthalenesulfonic acid. They are frequently used as fluorescent dyes and sulfhydryl reagents.
Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.
A phthalic indicator dye that appears yellow-green in normal tear film and bright green in a more alkaline medium such as the aqueous humor.
A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
The use of molecularly targeted imaging probes to localize and/or monitor biochemical and cellular processes via various imaging modalities that include RADIONUCLIDE IMAGING; ULTRASONOGRAPHY; MAGNETIC RESONANCE IMAGING; FLUORESCENCE IMAGING; and MICROSCOPY.
Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.
A naphthalene derivative with carcinogenic action.
Fluorescent probe capable of being conjugated to tissue and proteins. It is used as a label in fluorescent antibody staining procedures as well as protein- and amino acid-binding techniques.
Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
A group of condensed ring hydrocarbons.
The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
A colorless, odorless, highly water soluble vinyl monomer formed from the hydration of acrylonitrile. It is primarily used in research laboratories for electrophoresis, chromatography, and electron microscopy and in the sewage and wastewater treatment industries.
Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Proteins prepared by recombinant DNA technology.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Established cell cultures that have the potential to propagate indefinitely.
The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.
An extraction method that separates analytes using a solid phase and a liquid phase. It is used for preparative sample cleanup before analysis by CHROMATOGRAPHY and other analytical methods.
Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Proteins found in any species of bacterium.
Compounds that contain a 1-dimethylaminonaphthalene-5-sulfonyl group.
The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.
A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)
Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
A class of organic compounds that contains a naphthalene moiety linked to a sulfonic acid salt or ester.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.
A fluorescent compound that emits light only in specific configurations in certain lipid media. It is used as a tool in the study of membrane lipids.
Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.
The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Nanometer sized fragments of semiconductor crystalline material which emit PHOTONS. The wavelength is based on the quantum confinement size of the dot. They can be embedded in MICROBEADS for high throughput ANALYTICAL CHEMISTRY TECHNIQUES.
A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
The process of cleaving a chemical compound by the addition of a molecule of water.
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.
Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.
The systematic identification and quantitation of all the metabolic products of a cell, tissue, organ, or organism under varying conditions. The METABOLOME of a cell or organism is a dynamic collection of metabolites which represent its net response to current conditions.
The characteristic three-dimensional shape of a molecule.
The physical characteristics and processes of biological systems.
Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
A compound produced from succinyl-CoA and GLYCINE as an intermediate in heme synthesis. It is used as a PHOTOCHEMOTHERAPY for actinic KERATOSIS.
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.
Use of various chemical separation and extraction methods, such as SOLID PHASE EXTRACTION; CHROMATOGRAPHY; and SUPERCRITICAL FLUID EXTRACTION; to prepare samples for analytical measurement of components.
The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.
The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
A cell line derived from cultured tumor cells.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
A group of atoms or molecules attached to other molecules or cellular structures and used in studying the properties of these molecules and structures. Radioactive DNA or RNA sequences are used in MOLECULAR GENETICS to detect the presence of a complementary sequence by NUCLEIC ACID HYBRIDIZATION.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)
A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.
A broad class of substances containing carbon and its derivatives. Many of these chemicals will frequently contain hydrogen with or without oxygen, nitrogen, sulfur, phosphorus, and other elements. They exist in either carbon chain or carbon ring form.
A strong organic base existing primarily as guanidium ions at physiological pH. It is found in the urine as a normal product of protein metabolism. It is also used in laboratory research as a protein denaturant. (From Martindale, the Extra Pharmacopoeia, 30th ed and Merck Index, 12th ed) It is also used in the treatment of myasthenia and as a fluorescent probe in HPLC.
A tricarbocyanine dye that is used diagnostically in liver function tests and to determine blood volume and cardiac output.
Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)
Methods for assessing flow through a system by injection of a known quantity of an indicator, such as a dye, radionuclide, or chilled liquid, into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)
That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants.
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
The motion of phospholipid molecules within the lipid bilayer, dependent on the classes of phospholipids present, their fatty acid composition and degree of unsaturation of the acyl chains, the cholesterol concentration, and temperature.
Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.
The application of medical knowledge to questions of law.
Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.
The dynamic collection of metabolites which represent a cell's or organism's net metabolic response to current conditions.
The process by which two molecules of the same chemical composition form a condensation product or polymer.
A noninvasive technique that uses the differential absorption properties of hemoglobin and myoglobin to evaluate tissue oxygenation and indirectly can measure regional hemodynamics and blood flow. Near-infrared light (NIR) can propagate through tissues and at particular wavelengths is differentially absorbed by oxygenated vs. deoxygenated forms of hemoglobin and myoglobin. Illumination of intact tissue with NIR allows qualitative assessment of changes in the tissue concentration of these molecules. The analysis is also used to determine body composition.
The sum of the weight of all the atoms in a molecule.
Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)
The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.
Porphyrins with four methyl, two vinyl, and two propionic acid side chains attached to the pyrrole rings. Protoporphyrin IX occurs in hemoglobin, myoglobin, and most of the cytochromes.
Inorganic or organic compounds that contain boron as an integral part of the molecule.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Any visual display of structural or functional patterns of organs or tissues for diagnostic evaluation. It includes measuring physiologic and metabolic responses to physical and chemical stimuli, as well as ultramicroscopy.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
A benzofuran derivative used as a protein reagent since the terminal N-NBD-protein conjugate possesses interesting fluorescence and spectral properties. It has also been used as a covalent inhibitor of both beef heart mitochondrial ATPase and bacterial ATPase.
The characteristic 3-dimensional shape of a carbohydrate.
Colorless, odorless crystals that are used extensively in research laboratories for the preparation of polyacrylamide gels for electrophoresis and in organic synthesis, and polymerization. Some of its polymers are used in sewage and wastewater treatment, permanent press fabrics, and as soil conditioning agents.
Devices for accelerating charged particles in a spiral path by a constant-frequency alternating electric field. This electric field is synchronized with the movement of the particles in a constant magnetic field.
Methods for determining interaction between PROTEINS.
Drugs that are pharmacologically inactive but when exposed to ultraviolet radiation or sunlight are converted to their active metabolite to produce a beneficial reaction affecting the diseased tissue. These compounds can be administered topically or systemically and have been used therapeutically to treat psoriasis and various types of neoplasms.
Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.
A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.
Methods of creating machines and devices.
The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.
Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)
Mixtures of many components in inexact proportions, usually natural, such as PLANT EXTRACTS; VENOMS; and MANURE. These are distinguished from DRUG COMBINATIONS which have only a few components in definite proportions.
The use of devices which use detector molecules to detect, investigate, or analyze other molecules, macromolecules, molecular aggregates, or organisms.
A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.
Salts and esters of the 12-carbon saturated monocarboxylic acid--lauric acid.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.
A chromatography technique in which the stationary phase is composed of a non-polar substance with a polar mobile phase, in contrast to normal-phase chromatography in which the stationary phase is a polar substance with a non-polar mobile phase.
A trypanocidal agent and possible antiviral agent that is widely used in experimental cell biology and biochemistry. Ethidium has several experimentally useful properties including binding to nucleic acids, noncompetitive inhibition of nicotinic acetylcholine receptors, and fluorescence among others. It is most commonly used as the bromide.
The chemical and physical integrity of a pharmaceutical product.
Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.
Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
Europium. An element of the rare earth family of metals. It has the atomic symbol Eu, atomic number 63, and atomic weight 152. Europium is used in the form of its salts as coatings for cathode ray tubes and in the form of its organic derivatives as shift reagents in NMR spectroscopy.
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
A purine that is an isomer of ADENINE (6-aminopurine).

Relocating the active site of activated protein C eliminates the need for its protein S cofactor. A fluorescence resonance energy transfer study. (1/12106)

The effect of replacing the gamma-carboxyglutamic acid domain of activated protein C (APC) with that of prothrombin on the topography of the membrane-bound enzyme was examined using fluorescence resonance energy transfer. The average distance of closest approach (assuming kappa2 = 2/3) between a fluorescein in the active site of the chimera and octadecylrhodamine at the membrane surface was 89 A, compared with 94 A for wild-type APC. The gamma-carboxyglutamic acid domain substitution therefore lowered and/or reoriented the active site, repositioning it close to the 84 A observed for the APC. protein S complex. Protein S enhances wild-type APC cleavage of factor Va at Arg306, but the inactivation rate of factor Va Leiden by the chimera alone is essentially equal to that by wild-type APC plus protein S. These data suggest that the activities of the chimera and of the APC.protein S complex are equivalent because the active site of the chimeric protein is already positioned near the optimal location above the membrane surface to cleave Arg306. Thus, one mechanism by which protein S regulates APC activity is by relocating its active site to the proper position above the membrane surface to optimize factor Va cleavage.  (+info)

Mapping the functional domains of BRCA1. Interaction of the ring finger domains of BRCA1 and BARD1. (2/12106)

Breast cancer 1 (BRCA1) and BRCA1-associated RING domain 1 (BARD1) are multidomain proteins that interact in vivo via their N-terminal RING finger motif regions. To characterize functional aspects of the BRCA1/BARD1 interaction, we have defined the structural domains required for the interaction, as well as their oligomerization state, relative stability, and possible nucleic acid binding activity. We have found that the RING finger motifs do not themselves constitute stable structural domains but are instead part of larger domains comprising residues 1-109 of BRCA1 and residues 26-119 of BARD1. These domains exist as homodimers and preferentially form a stable heterodimer. Shorter BRCA1 RING finger constructs do not interact with BARD1 or with longer BRCA1 constructs, indicating that the heterodimeric and homodimer interactions are mediated by regions outside the canonical RING finger motif. Nucleic acid binding is a generally proposed function of RING finger domains. We show that neither the homodimers nor the heterodimer displays affinity for nucleic acids, indicating that the proposed roles of BRCA1 and BARD1 in DNA repair and/or transcriptional activation must be mediated either by other regions of the proteins or by additional cofactors.  (+info)

Tolerance of a protein to multiple polar-to-hydrophobic surface substitutions. (3/12106)

Hydrophobic substitutions at solvent-exposed positions in two alpha-helical regions of the bacteriophage P22 Arc repressor were introduced by combinatorial mutagenesis. In helix A, hydrophobic residues were tolerated individually at each of the five positions examined, but multiple substitutions were poorly tolerated as shown by the finding that mutants with more than two additional hydrophobic residues were biologically inactive. Several inactive helix A variants were purified and found to have reduced thermal stability relative to wild-type Arc, with a rough correlation between the number of polar-to-hydrophobic substitutions and the magnitude of the stability defect. Quite different results were obtained in helix B, where variants with as many as five polar-to-hydrophobic substitutions were found to be biologically active and one variant with three hydrophobic substitutions had a t(m) 6 degrees C higher than wild-type. By contrast, a helix A mutant with three similar polar-to-hydrophobic substitutions was 23 degrees C less stable than wild-type. Also, one set of three polar-to-hydrophobic substitutions in helix B was tolerated when introduced into the wild-type background but not when introduced into an equally active mutant having a nearly identical structure. Context effects occur both when comparing different regions of the same protein and when comparing the same region in two different homologues.  (+info)

Folding of apocytochrome c induced by the interaction with negatively charged lipid micelles proceeds via a collapsed intermediate state. (4/12106)

Unfolded apocytochrome c acquires an alpha-helical conformation upon interaction with lipid. Folding kinetic results below and above the lipid's CMC, together with energy transfer measurements of lipid bound states, and salt-induced compact states in solution, show that the folding transition of apocytochrome c from the unfolded state in solution to a lipid-inserted helical conformation proceeds via a collapsed intermediate state (I(C)). This initial compact state is driven by a hydrophobic collapse of the polypeptide chain in the absence of the heme group and may represent a heme-free analogue of an early compact intermediate detected on the folding pathway of cytochrome c in solution. Insertion into the lipid phase occurs via an unfolding step of I(C) through a more extended state associated with the membrane surface (I(S)). While I(C) appears to be as compact as salt-induced compact states in solution with substantial alpha-helix content, the final lipid-inserted state (Hmic) is as compact as the unfolded state in solution at pH 5 and has an alpha-helix content which resembles that of native cytochrome c.  (+info)

Esterases in serum-containing growth media counteract chloramphenicol acetyltransferase activity in vitro. (5/12106)

The spirochete Borrelia burgdorferi was unexpectedly found to be as susceptible to diacetyl chloramphenicol, the product of the enzyme chloramphenicol acetyltransferase, as it was to chloramphenicol itself. The susceptibilities of Escherichia coli and Bacillus subtilis, as well as that of B. burgdorferi, to diacetyl chloramphenicol were then assayed in different media. All three species were susceptible to diacetyl chloramphenicol when growth media were supplemented with rabbit serum or, to a lesser extent, human serum. Susceptibility of E. coli and B. subtilis to diacetyl chloramphenicol was not observed in the absence of serum, when horse serum was used, or when the rabbit or human serum was heated first. In the presence of 10% rabbit serum, a strain of E. coli bearing the chloramphenicol acetyltransferase (cat) gene had a fourfold-lower resistance to chloramphenicol than in the absence of serum. A plate bioassay for chloramphenicol activity showed the conversion by rabbit, mouse, and human sera but not bacterial cell extracts or heated serum of diacetyl chloramphenicol to an inhibitory compound. Deacetylation of acetyl chloramphenicol by serum components was demonstrated by using fluorescent substrates and thin-layer chromatography. These studies indicate that esterases of serum can convert diacetyl chloramphenicol back to an active antibiotic, and thus, in vitro findings may not accurately reflect the level of chloramphenicol resistance by cat-bearing bacteria in vivo.  (+info)

Morphological behavior of acidic and neutral liposomes induced by basic amphiphilic alpha-helical peptides with systematically varied hydrophobic-hydrophilic balance. (6/12106)

Lipid-peptide interaction has been investigated using cationic amphiphilic alpha-helical peptides and systematically varying their hydrophobic-hydrophilic balance (HHB). The influence of the peptides on neutral and acidic liposomes was examined by 1) Trp fluorescence quenched by brominated phospholipid, 2) membrane-clearing ability, 3) size determination of liposomes by dynamic light scattering, 4) morphological observation by electron microscopy, and 5) ability to form planar lipid bilayers from channels. The peptides examined consist of hydrophobic Leu and hydrophilic Lys residues with ratios 13:5, 11:7, 9:9, 7:11, and 5:13 (abbreviated as Hels 13-5, 11-7, 9-9, 7-11, and 5-13, respectively; Kiyota, T., S. Lee, and G. Sugihara. 1996. Biochemistry. 35:13196-13204). The most hydrophobic peptide (Hel 13-5) induced a twisted ribbon-like fibril structure for egg PC liposomes. In a 3/1 (egg PC/egg PG) lipid mixture, Hel 13-5 addition caused fusion of the liposomes. Hel 13-5 formed ion channels in neutral lipid bilayer (egg PE/egg PC = 7/3) at low peptide concentrations, but not in an acidic bilayer (egg PE/brain PS = 7/3). The peptides with hydrophobicity less than Hel 13-5 (Hels 11-7 and Hel 9-9) were able to partially immerse their hydrophobic part of the amphiphilic helix in lipid bilayers and fragment liposome to small bicelles or micelles, and then the bicelles aggregated to form a larger assembly. Peptides Hel 11-7 and Hel 9-9 each formed strong ion channels. Peptides (Hel 7-11 and Hel 5-13) with a more hydrophilic HHB interacted with an acidic lipid bilayer by charge interaction, in which the former immerses the hydrophobic part in lipid bilayer, and the latter did not immerse, and formed large assemblies by aggregation of original liposomes. The present study clearly showed that hydrophobic-hydrophilic balance of a peptide is a crucial factor in understanding lipid-peptide interactions.  (+info)

Localization and environment of tryptophans in soluble and membrane-bound states of a pore-forming toxin from Staphylococcus aureus. (7/12106)

The location and environment of tryptophans in the soluble and membrane-bound forms of Staphylococcus aureus alpha-toxin were monitored using intrinsic tryptophan fluorescence. Fluorescence quenching of the toxin monomer in solution indicated varying degrees of tryptophan burial within the protein interior. N-Bromosuccinimide readily abolished 80% of the fluorescence in solution. The residual fluorescence of the modified toxin showed a blue-shifted emission maximum, a longer fluorescence lifetime as compared to the unmodified and membrane-bound alpha-toxin, and a 5- to 6-nm red edge excitation shift, all indicating a restricted tryptophan environment and deeply buried tryptophans. In the membrane-bound form, the fluorescence of alpha-toxin was quenched by iodide, indicating a conformational change leading to exposure of some tryptophans. A shorter average lifetime of tryptophans in the membrane-bound alpha-toxin as compared to the native toxin supported the conclusions based on iodide quenching of the membrane-bound toxin. Fluorescence quenching of membrane-bound alpha-toxin using brominated and spin-labeled fatty acids showed no quenching of fluorescence using brominated lipids. However, significant quenching was observed using 5- and 12-doxyl stearic acids. An average depth calculation using the parallax method indicated that the doxyl-quenchable tryptophans are located at an average depth of 10 A from the center of the bilayer close to the membrane interface. This was found to be in striking agreement with the recently described structure of the membrane-bound form of alpha-toxin.  (+info)

Photophysical analysis of class I major histocompatibility complex protein assembly using a xanthene-derivatized beta2-microglobulin. (8/12106)

Spectral changes and a sixfold increase in the emission intensity were observed in the fluorescence of a single xanthene probe (Texas red) attached to beta2m-microglobulin (beta2m) upon assembly of beta2m into a ternary complex with mouse H-2Kd heavy chain and influenza nuclear protein peptide. Dissociation of the labeled beta2m from the ternary complex restored the probe's fluorescence and absorption spectra and reduced the emission intensity. Thus changes in xanthene probe fluorescence upon association/dissociation of the labeled beta2m molecule with/from the ternary complex provide a simple and convenient method for studying the assembly/dissociation mechanism of the class I major histocompatibility complex (MHC-I) encoded molecule. The photophysical changes in the probe can be accounted for by the oligomerization of free labeled beta2m molecules. The fluorescence at 610 nm is due to beta2m dimers, where the probes are significantly separated spatially so that their emission and excitation properties are close to those of xanthene monomers. Fluorescence around 630 nm is due to beta2m oligomers where xanthene probes interact. Minima in the steady-state excitation (550 nm) and emission (630 nm) anisotropy spectra correlate with the maxima of the high-order oligomer excitation and emission spectra, showing that their fluorescence is more depolarized. These photophysical features are explained by splitting of the first singlet excited state of interacting xanthene probes that can be modeled by exciton theory.  (+info)

BAVILI TABRIZI, Ahad y DEHGHANI TEYMURLOUIE, Nadereh. Application of Sodium Dodecyl Sulfate Coated Iron Oxide Magnetic Nanoparticles for the Extraction and Spectrofluorimetric Determination of Propranolol in Different Biological Samples. J. Mex. Chem. Soc [online]. 2016, vol.60, n.3, pp.108-116. ISSN 1870-249X.. A new analytical approach was developed involving magnetic solid-phase extraction (MSPE) and spectrofluorimetric determination of propranolol (PRO) in biological fluids. A urine or plasma sample was prepared and adjusted to pH 3-4, then PRO was quickly extracted using Fe3O4 magnetic nanoparticles (MNPs) modified by the surfactant sodium dodecyl sulfate (SDS) and determined applying spectrofluorimetry. Experimental conditions, such as the amount of MNPs and SDS, pH value, standing time, desorption solvent and maximal extraction volume have been adjusted to optimize the extraction process and to obtain analytical characteristics of the method. Linearity was observed in the analytes ...
TY - JOUR. T1 - Multispectral scanning time-resolved fluorescence spectroscopy (TRFS) technique for intravascular diagnosis. AU - Xie, Hongtao. AU - Bec, Julien. AU - Liu, Jing. AU - Sun, Yang. AU - Lam, Matthew. AU - Yankelevich, Diego R.. AU - Marcu, Laura. PY - 2012/7/1. Y1 - 2012/7/1. N2 - This study describes a scanning time-resolved fluorescence spectroscopy (TRFS) system designed to continuously acquire fluorescence emission and to reconstruct fluorescence lifetime images (FLIM) from a luminal surface by using a catheter-based optical probe with rotary joint and pull-back device. The ability of the system to temporally and spectrally resolve the fluorescence emission from tissue was validated using standard dyes and tissue phantoms (e.g., ex vivo pig aorta phantom). Current results demonstrate that this system is capable to reliably resolve the fluorescence emission of multiple fluorophores located in the lumen; and suggest its potential for intravascular detection of distinct biochemical ...
A rapid, simple and sensitive synchronous specrtofluorimetric method has been developed for the simultaneous analysis of binary mixture of metoprolol (MTP) and felodipine (FDP). The method is based upon measurement of the synchronous fluorescence intensity of the two drugs at Δλ of 70 nm in aqueous solution. The different experimental parameters affecting the synchronous fluorescence intensities of the two drugs were carefully studied and optimized. The fluorescence intensity-concentration plots were rectilinear over the ranges of 0.5-10 μg/mL and 0.2-2 μg/mL for MTP and FDP, respectively. The limits of detection were 0.11 and 0.02 μg/mL and quantification limits were 0.32 and 0.06 μg/mL for MTP and FDP, respectively. The proposed method was successfully applied for the determination of the two compounds in their commercial tablets and the results obtained were favorably compared to those obtained with a comparison method.
The paper reviewed the application these years of fluorescence spectrophotometry in environmental monitoring.The content includes the principle,the establishment of methods,the study of fluorescence system and the development of the combination with other techniques. It indicated that fluorescence method is sensitive, selective, less sample using and simple. It is an effective way for the analysis of trace elements and substances in complicated environmental samples. It will have a broad prospect in environmental analysis with the combination with other techniques.
TY - JOUR. T1 - Steady-state and time-resolved fluorescence spectroscopic studies on interaction of the N-terminal region with the hairpin loop of the phytocystain Scb. AU - Doi-Kawano, Keiko. AU - Nishimoto, Etsuko. AU - Kouzuma, Yoshiaki. AU - Takahashi, Daisuke. AU - Yamashita, Shoji. AU - Kimura, Makoto. PY - 2009/7/1. Y1 - 2009/7/1. N2 - The steady-state and time-resolved fluorescece spectroscopy is one of the most powerful method to detect and analyze subtle conformation change and interaction between peptide elements in protein. Phytocystatin Scb isolated from sunflower seeds includes a single Trp residue at position 85. In an attempt to investigate the interaction of the N-terminal region of Scb with the first and second hairpin loops by fluorescence spectroscopy of Trp residue, two Scb mutants in which single Trp locates at position 52 and 58, respectively, and their N-terminal removed mutants were generated. The N-terminal truncation changed the fluorescence decay kinetics of Trp52 ...
TY - JOUR. T1 - Fluorescence correlation spectroscopy of finite-sized particles. AU - Wu, Bin. AU - Chen, Yan. AU - Müller, Joachim D.. PY - 2008/4. Y1 - 2008/4. N2 - A theory is presented to study fluorescence correlation spectroscopy for particles with size comparable to the beam waist of the observation volume. Analytical correlation curves are derived for some experimentally interesting particle geometries. It is found that the finiteness of the particle generally decreases the value of the correlation amplitude and increases the correlation time compared to a point particle model. Furthermore, not only the size but also the distribution of fluorophores affects the shape of the correlation function. This is experimentally demonstrated with surface and internally labeled fluorescent spheres. In addition, experiments are performed on fluorescent spheres of different radii to validate the model by comparing the results to theoretical predictions.. AB - A theory is presented to study ...
TY - JOUR. T1 - Detection of Pentosidine Cross-Links in Cell-Secreted Decellularized Matrices Using Time Resolved Fluorescence Spectroscopy. AU - Mitra, Debika. AU - Fatakdawala, Hussain. AU - Nguyen-Truong, Michael. AU - Creecy, Amy. AU - Nyman, Jeffry. AU - Marcu, Laura. AU - Leach, Jonathan K. PY - 2017/9/11. Y1 - 2017/9/11. N2 - Hyperglycemia-mediated, nonenzymatic collagen cross-links such as pentosidine (PENT) can have deleterious effects on cellular interactions with the extracellular matrix (ECM). Present techniques to quantify PENT are limited, motivating the need for improved methods to study the accumulation and contribution of PENT toward diabetic clinical challenges such as impaired bone healing. Current methods for studying PENT are destructive, laborious, and frequently employ oversimplified collagen films that lack the complexity of the native ECM. The primary goal of this study was to evaluate the capacity of time-resolved fluorescence spectroscopy (TRFS) to detect PENT in ...
We compared various spectroscopic properties of a norfloxacin-single stranded DNA complex with those of norfloxacin-double stranded DNA complex. Norfloxacin binds to both double- and single stranded DNA, and we observed the following spectroscopic changes for both complexes: hypochromism in the norfloxacin absorption region in the absorption spectrum, the characteristic induced CD spectrum consisting of a weak positive band at 323 nm and a strong positive band at 280-300 nm followed by a negative band in the 260 nm region, a strong decrease in the fluorescence intensity and a red-shift in the fluorescence emission spectrum, and shorter fluorescence decay times. These results indicate that the environments of the bound norfloxacin in both DNAs are similar, although the equilibrium constant of the norfloxacin-single stranded DNA was twice as high as the norfloxacin-double stranded DNA complex. Both complexes were thermodynamically favored with similar negative ΔGo. Negative ΔHo terms contribute ...
Berland, K.M., So, P.T., Gratton, E. 1995. Two-photon fluorescence correlation spectroscopy: method and application to the intracellular environment. Biophys J. 68(2):694-701. PubMed. Chen Y, Müller JD, So PTC, Gratton E. 1999. The photon counting histogram in fluorescence fluctuation spectroscopy. Biophys J. 77: 553-567. PubMed. Elson EL. 2001. Fluorescence correlation spectroscopy measures molecular transport in cells. Traffic 2(11):789-96. PubMed. Elson EL, Magde D. 1974. Fluorescence correlation spectroscopy. I. Conceptual basis and theory. Biopolymers, 13(1):1-27. Kask P, Palo K, Ullmann D and Gall K. 1999. Fluorescence-intensity distribution analysis and its application in biomolecular detection technology. Proc Natl Acad Sci USA 96:13756-13761. PubMed Kis-Petikova K, Chen Y, Müeller JD, Gratton E. 2000. Application of scanning fluorescent correlation spectroscopy for determination of particle shape. Biophys. J., 78(1), 2603. Koppel DE, Axelrod D, Schlessinger J, Elson EL, Webb WW. 1976. ...
291309859 - EP 1259805 A1 2002-11-27 - LIPOPROTEIN ASSAY - [origin: WO0153829A1] A method of assaying to determine the identity and/or concentration or relative concentration in a sample solution of a particular one of a number of different target molecule types, comprise the steps of: i) adding to the sample a probe substance which binds to the or each target molecule type and which when so bound fluoresces under appropriate excitation; ii) performing a time-resolved fluorescence measurement on the sample; and iii) making said determination from analysis of the time decay data obtained from said time-resolved fluorescence measurement.[origin: WO0153829A1] A method of assaying to determine the identity and/or concentration or relative concentration in a sample solution of a particular one of a number of different target molecule types, comprise the steps of: i) adding to the sample a probe substance which binds to the or each target molecule type and which when so bound fluoresces under appropriate
The detailed analysis of the processes of electronic energy relaxation in a substance, taking place after the short optical impulses of excitation, shows that mathematical models of the detected optical intensity decay can not be expressed by a combination of elementary mathematical functions. In the present work we suggest the approach to the parameter estimation of the decay curves, obtained from the time-resolved fluorescence experiments, based on the computer simulation methods. By means of simulation elementary processes of energy relaxation can be reproduced with the highest level of the detailed elaboration. Given processes are characterized by a set of parameters which have to be estimated. For the estimation we tried several methods, which do not require calculation of the derivatives, as in widespread Marquardt algorithm, that could be difficult for the decay curves, represented by a simulation model. The main advantage of the proposed approach is that it is possible to estimate the ...
Article Three-dimensional excitation emission matrix fluorescence spectroscopy and gel-permeating chromatography to characterize extracellular polymeric substances in aerobic granulation. Three-dimensional excitation emission matrix (EEM) fluorescenc...
Steady State Spectrofluorometer from HORIBA Scientific. The FluoroLog-3, a modular instrument, is the Worlds Most Sensitive Spectrofluorometer
Fluorescence correlation spectroscopy (FCS) is a very useful tool for examining mobility and interactions in a variety of systems including membranes. FCS is highly sensitive to small differences in the diffusion rates of proteins and lipids, which allows for instance to characterize differences in phase behavior of lipid bilayers. FCS is used to analyze the binding of diffusible ligands to membrane receptors, such as membrane proteins or glycolipids. Changes in the fluorescence brightness parameter reveal membrane protein oligomerization. Moreover, the use of dual-color fluorescence cross-correlation (dcFCCS) allows to assess protein-protein binding in cases, where binding does not lead to significant changes in diffusion rates. The dual-color cross-correlation technique can also be employed to detect dynamic co-localization of labeled cargo molecules in small, mobile carriers, such as transport vesicles. Owing to the use of fluorescent labels, FCS is highly specific and can be applied both to ...
In flow cytometry, the fluorescence decay time of an excitable species has been largely underutilized and is not likely found as a standard parameter on any imaging cytometer, sorting, or analyzing system
Nanosecond time-resolved emission spectral techniques have been applied to the problem of the origin and nature of the well-known temperature-dependent spectral shifts characteristic of the aminophthalimides in alcohol solvents. It is demonstrated that the temperature-dependent spectral shifts are in fact due to time-dependent spectral shifts. At least two relaxation times characterize this phenomenon. One relaxation time is observed to be subnanosecond in character and may be associated with the exciplex that presumably is present in the system. The other relaxation time is presumably associated with the non-specific dipolar reorientation although it has distinctly different characteristics from the solvent dielectric relaxation time. Wavelength-dependent fluorescence decay that can be explained by the time dependence of the emission spectrum is also observed. (Author)(*IMIDES
Department of Biological Sciences, Texas Tech University, Lubbock 79409, USA. [email protected] The function of Lhca4, a gene encoding the photosystem 1 type IV chlorophyll a/b-binding protein complex in Arabidopsis, was investigated using antisense technology. Lhca4 protein was reduced in a number of mutant lines and abolished in one. The inhibition of protein was not correlated with the inhibition of mRNA. No depletion of Lhca1 was observed, but the low-temperature fluorescence emission spectrum was drastically altered in the mutants. The emission maximum was blue-shifted by 6 nm, showing that chlorophyll molecules bound to Lhca4 are responsible for most of the long-wavelength fluorescence emission. Some mutants also showed an unexplainable delay in flowering time and an increase in seed weight.. MeSH Terms ...
To understand the function of cellular protein networks, spatial and temporal context is essential. Fluorescence correlation spectroscopy (FCS) is a single-molecule method to study the abundance, mobility and interactions of fluorescence-labeled biomolecules in living cells. However, manual acquisition and analysis procedures have restricted live-cell FCS to short-term experiments of a few proteins. Here, we present high-throughput (HT)-FCS, which automates screening and time-lapse acquisition of FCS data at specific subcellular locations and subsequent data analysis. We demonstrate its utility by studying the dynamics of 53 nuclear proteins. We made 60,000 measurements in 10,000 living human cells, to obtain biophysical parameters that allowed us to classify proteins according to their chromatin binding and complex formation. We also analyzed the cell-cycle-dependent dynamics of the mitotic kinase complex Aurora B/INCENP and showed how a rise in Aurora concentration triggers two-step complex ...
Background: The accumulation of fibrillar deposits of amyloid beta-peptide (A beta) in brain parenchyma and cerebromeningeal blood vessels is a key step in the pathogenesis of Alzheimers disease. In this report, polymerization of A beta was studied using fluorescence correlation spectroscopy (FCS), a technique capable of detecting small molecules and large aggregates simultaneously in solution. Results: The polymerization of A beta dissolved in Tris-buffered saline, pH 7.4, occurred above a critical concentration of 50 mu M and proceeded from monomers/dimers into two discrete populations of large aggregates, without any detectable amount of oligomers. The aggregation showed very high cooperativity and reached a maximum after 40 min, followed by an increase in the amount of monomers/dimers and a decrease in the size of the large aggregates. Electron micrographs of samples prepared at the time for maximum aggregation showed a mixture of an amorphous network and short diffuse fibrils, whereas only ...
The retinoic acid receptor (RAR) is a member of the nuclear receptor superfamily. This ligand‐inducible transcription factor binds to DNA as a heterodimer with the retinoid X receptor (RXR) in the nucleus. The nucleus is a dynamic compartment and live‐cell imaging techniques make it possible to investigate transcription factor action in real‐time. We studied the diffusion of EGFP-RAR by fluorescence correlation spectroscopy (FCS) to uncover the molecular interactions determining receptor mobility. In the absence of ligand, we identified two distinct species with different mobilities. The fast component has a diffusion coefficient of D1 = 1.8−6.0 µm2/second corresponding to small oligomeric forms, whereas the slow component with D2 = 0.05−0.10 µm2/second corresponds to interactions of RAR with the chromatin or other large structures. The RAR ligand‐binding‐domain fragment also has a slow component, probably as a result of indirect DNA‐binding through RXR, with lower affinity ...
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We report a novel, compact and automated multidimensional spectrofluorometer that exploits a fibre-laser-pumped ultrafast supercontinuum source to provide resolution with respect to intensity, excitation and emission wavelength, decay time and polarisation. This instrument has been applied to study the photophysics of the phase-sensitive membrane probe di-4-ANEPPDHQ and to characterise protein-protein interactions via Förster resonance energy transfer. It can be applied to in situ measurements via a fibre-optic probe in medical and other contexts and is demonstrated here to provide a comprehensive characterisation of tissue autofluorescence.
We demonstrate a smartphone-integrated handheld detection instrument capable of utilizing the internal rear-facing camera as a high-resolution spectrometer for measuring the colorimetric absorption spectrum, fluorescence emission spectrum, and resonant reflection spectrum from a microfluidic cartridge insert
Rhodopsin self-associates in the plasma membrane. At low concentrations, the interactions are consistent with a monomer-dimer equilibrium (Comar et al., J Am Chem Soc 136(23):8342-8349, 2014). At high
Metallic nano-antennas provide strong field confinement and intensity enhancement in hotspots and thus can ultimately enhance fluorescence detection and provide ultra small detection volumes. In solution-based fluorescence measurements, the diffraction limited focus driving the nano-antenna can outshine the fluorescence originating from the hotspot and thus render the benefits of the hotspot negligible. We introduce a model to calculate the effect of a nano-antenna, or any other object creating a nontrivial intensity distribution, for fluorescence fluctuation measurements. Approximating the local field enhancement of the nano-antenna by a 3D Gaussian profile, we show which hotspot sizes and intensities are the most beneficial for an FCS measurement and compare it to realistic antenna parameters from literature.. © 2014 Optical Society of America. Full Article , PDF Article ...
Read independent reviews on NANOPHOX - Photon Cross-correlation Spectroscopy for size and stability analysis of nano-suspensions and emulsions from 1 nm to 10,000 nm from Sympatec GmbH on SelectScience
Transmembrane domains (TMD) connect the inner with the outer world of a living cell. Single TMD containing (bitopic) receptors are of particular interest, because their oligomerization seems to be a common activation mechanism in cell signaling. We analyzed the composition of TMDs in bitopic proteins within the proteomes of 12 model organisms. The average number of strongly polar and charged residues decreases during evolution, while the occurrence of a dimerization motif, GxxxG, remains unchanged. This may reflect the avoidance of unspecific binding within a growing receptor interaction network. In addition, we propose a new experimental approach for studying helix-helix interactions in giant plasma membrane vesicles using scanning fluorescence cross-correlation spectroscopy. Measuring eGFP/mRFP tagged versions of cytokine receptors confirms the homotypic interactions of the erythropoietin receptor in contrast to the Interleukin-4 receptor chains. As a proof of principle, by swapping the TMDs, ...
This invention relates to a diagnostic apparatus and particularly to an apparatus for the diagnosis of malignant tumor and the method of using the apparatus for diagnosis. The apparatus employs an ultraviolet light source with an emitting waveband of 3000A-4000A. Light from the light source is transmitted through a bundle of quartz optic fibers to the surface of the tumor, whether benign or malignant, to stimulate it, which then generates a specific intrinsic fluorescence spectrum. The intrinsic fluorescence spectrum reflected from the surface of the tumor is transmitted by a second bundles of glass fibers placed near it to a color resolution means, then processed by a scanning means and a circuit means, and displayed recorded by a display recording means. The display may be a graphic presentation of the intrinsic fluorescence spectrum of the tumor that is tested. If the graphic presentation displayed includes a single peak within the range of the blue color band, it indicates that the tumor being
Abstract A study of the photoluminescence excitation spectrum in a crystal of mercury diiodide is reported. Each of the two luminescence bands peaking at 543 and 572-575 nm investigated was found to have its own excitation spectrum. The excitation spectrum of the 575-nm line in the... mehr ...
Fast and non-invasive, diagnostic techniques based on fluorescence spectroscopy have the potential to link the biochemical and morphologic properties of tissues to individual patient care. One of the most widely explored applications of fluorescence spectroscopy is the detection of endoscopically invisible, early neoplastic growth in epithelial tissue sites. Currently, there are no effective diagnostic techniques for these early tissue transformations. If fluorescence spectroscopy can be applied successfully as a diagnostic technique in this clinical context, it may increase the potential for curative treatment, and thus, reduce complications and health care costs. Steady-state, fluorescence measurements from small tissue regions as well as relatively large tissue fields have been performed. To a much lesser extent, time-resolved, fluorescence measurements have also been explored for tissue characterization. Furthermore, sources of both intrinsic (endogenous fluorophores) and extrinsic ...
TY - JOUR. T1 - Highly photostable ketopyrrolyl-BODIPYs with red aggregation-induced emission characteristics for ultrafast wash-free mitochondria-targeted bioimaging. AU - Wu, Hao. AU - Guo, Xing. AU - Yu, Changjiang. AU - Wong, Wai Yeung. AU - Hao, Erhong. AU - Jiao, Lijuan. PY - 2020/5. Y1 - 2020/5. N2 - Subcellular organelle-specific probes, including mitochondria-targeted fluorescent probes, have attracted enormous research interests because they can monitor or visualize the morphology or biological activities of specific organelles and play an indispensable role in disease diagnosis. To follow the process, highly specific and photostable fluorescent probes are in demand. However, commercially available mitochondria probes normally suffer from poor photostability under laser irradiation and aggregation caused quenching (ACQ) in the aggregate state. In this work, two simple aggregation-induced emission(AIE)-active meso-2-ketopyrrolyl BODIPYs were developed via a convenient one-pot synthetic ...
There are various fluorescent probes such as ANS (anilinonapthalene 8-sulphonate) and N-methyl-2-anilino-6-naphthalene sulphonate (MNS). They both contain charged and hydrophobic areas and therefore are situated at the water-lipid interface of the membrane. The fluorescent properties of the molecule vary with its mobility and also with the polarity of the environment. Studies with the ANS probe has shown that structural changes occur in mitochondrial membrane during oxidative phosphorylation. These probes have also helped in giving information about the structural features of the plasma membrane. ...
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Single-molecule fluorescence spectroscopy and super-resolution microscopy are important elements of the ongoing technical revolution to reveal biochemical and cellular processes in unprecedented clarity and precision. Demands placed on the photophysical properties of the fluorophores are stringent a …
A new imaging contrast agent is reported that provides an increased fluorescent signal upon application of ultrasound (US). Liposomes containing lipids labelled with pyrene were optically excited and the excimer fluorescence emission intensity was detected in the absence and presence of an ultrasound field using an acousto-fluorescence setup. The acousto-fluorescence dynamics of liposomes containing lipids with pyrene labelled on the fatty acid tail group (PyPC) and the head group (PyPE) were compared. An increase in excimer emission intensity following exposure to US was observed for both cases studied. The increased intensity and time constants were found to be different for the PyPC and PyPE systems, and dependent on the applied US pressure and exposure time. The greatest change in fluorescence intensity (130%) and smallest rise time constant (0.33 s) are achieved through the use of PyPC labelled liposomes. The mechanism underlying the observed increase of the excimer emission intensity in ...
Calcium ions play an important role in cell function, acting as effectors and/or signaling molecules for a variety of cellular biochemical and physiological processes. The development of a variety of Ca2+-sensitive fluorescent indicators and advancements in imaging technology have enhanced the ability to follow both global and localized changes in intracellular Ca2+ at ever improving temporal and spatial resolution. Ratiometric Ca2+ indicators like fura-2 permit the measurement of intracellular Ca2+ concentration (Grynkiewicz et al., 1985). But, they tend to have a limited dynamic range and a significant fluorescence background, which reduce their sensitivity to small local increases in Ca2+. On the other hand, certain nonratiometric Ca2+ indicators, such as fluo-3, although not able to give a dynamic direct read-out of the Ca2+ concentration, have very low fluorescence when not bound to Ca2+ and have a significant increase in fluorescence intensity upon binding Ca2+ (e.g., ∼200 times for ...
This thesis describes the development of sensitive and high-resolution fluorescence spectroscopic and microscopic techniques and their application to probe biomolecules and their interactions in solution, lipid membrane model systems and in cells. Paper I-IV are largely focused on methodological developments. In paper I, a new fluorescence method based on fluorescence correlation spectroscopy (FCS) for detecting single particles was realized, requiring no fluorescent labeling of the particles. The method can yield information both about the diffusion properties of the particles as well as about their volumes. In paper II, a modified fluorescence cross correlation spectroscopy procedure with well characterized instrumental calibration was developed and applied to study cis interactions between an inhibitory receptor and its Major Histocompatibility Complex class I ligand molecule, both within the same cellular membranes. The quantitative analysis brought new insights into the Nature killer cells ...
Some APC-Cy7 conjugates show changes in their emission spectra with prolonged exposure to paraformaldehyde. For instruments equipped with a 561 nm Yellow-Green laser, a 585/15 nm filter is recommended for detection. When making decisions about which fluorochromes to use in your experiments, youll want to know their relative emission spectra. APC (Allophycocyanin) spectrum - APC (Allophycocyanin) is ... excitation and emission wavelengths using the interactive Spectrum Viewer - A web application for viewing and comparing spectra of various fluorescent compounds. BV605 is a tandem fluorochrome that combines BD Horizon BV421 and an acceptor dye with emission at 605nm. APC-H7 conjugates provide greater stability in light and paraformaldehyde fixatives and have less spillover into the APC channel than APC-Cy7 conjugates. However, because of its peak emission at 667 nm, Alexa Fluor® 647 cannot be seen well by eye, and it cannot be excited optimally with a mercury lamp. BV650 is a tandem fluorochrome ...
The cell membrane is organized in to different structures and it has been difficult to visualize these structures since they are believed to possess sizes below the optical resolution limit. Hence the development of new tools probing the biophysical properties of membranes is necessary. Imaging FCS is one such tool which allows the measurement of mobility at contiguous locations on cell membranes of live cells by analyzing the autocorrelation functions. In this thesis, Imaging FCS is being extended to Imaging FCCS enabling one to calculate cross-correlations and to extract parameters from the same. The next part discusses methods to characterize organization of membranes. The last part describes the study of membrane proteins and anti-microbials carried out using Imaging FCS. Unlike single point FCS which yields only mobility, imaging FCS provides mobility and heterogeneity and proved to be a valuable biophysical tool to characterize the dynamics and organization of cell membranes ...
To enable not only long sequence read but also high throughput in a DNA sequencer, the single molecule sequencing method based on direct observation of processive DNA polymerization is very promising. In this method, only incorporated nucleotides labeled with fluorescent dye should be detected under high concentration of unreacted nucleotides. Enhanced local field produced by plasmonic nanostructure is very suitable for such application because of its small size of a few ten nanometers. We have fabricated platinum bowtie nanostructure arrays producing fluorescence enhancement and have evaluated the performance using two-photon photoluminescence and single molecule fluorescence measurements. To enable use of multicolor dye labeling, visible light excitation around 500 nm is preferable, so that gold well known as a plasmonic material cannot be used. We explored suitable materials comprehensively by electromagnetic simulation and consequently chose platinum. Observation of bright photoluminescence from Pt
The single-molecule spectroscopy group is engaged in the development of new methods of single-molecule fluorescence spectroscopy and related photon data analysis. By utilizing the developed methods, we investigate the complex behavior of biomolecular systems, such as proteins, nucleic acids, and lipid membranes. Through the integrated approach of laser spectroscopy, biophysical chemistry, and statistical data analysis, we pursue creating a new field of molecular science ...
PA-Mode Single Wavelength allows the detection and fusion of photoacoustic signals with detailed anatomical images. Using a tuneable near infrared laser, the subject is illuminated at the desired wavelength (680-970nm and 1200-2000nm*) in order to visualize chromophores such as hemoglobin, melanin, dyes and nanoparticles.
What is Fluorescence Spectroscopy? Fluorescence is a type of luminescence caused by photons exciting a molecule, raising it to an electronic excited state. Overview of what is fluorescence, what is a fluorescence spectrum, what materials exhibit fluorescence.
TY - JOUR. T1 - Radiative and non-radiative decays from the excited state of Ti3+ ions in oxide crystals. AU - Yamaga, M.. AU - Gao, Y.. AU - Rasheed, F.. AU - ODonnell, K. P.. AU - Henderson, B.. AU - Cockayne, B.. PY - 1990/11/1. Y1 - 1990/11/1. N2 - The fluorescence spectra of Ti3+ in Y3Al5O12 (YAG), Al2O3 (sapphire), YAlO3 (YAP) observed at 10 K are composed of zero-phonon lines accompanied by the broad vibronic sidebands. The temperature dependence of the fluorescence lifetime and of the total intensity of the broadband measured in YAG and Al2O3 indicate that the radiative decay times from the excited states are nearly constant in the range 10-300 K. This demonstrates that the broadband radiative emissions in Ti3+:YAG and Ti3+:Al2O3 are due to magnetic dipole transitions or to electric dipole transitions induced by static odd-parity distortion, respectively. The decrease of the fluorescence lifetime with increasing temperature in Ti3+:YAG and Ti3+:Al2O3 is due to non-radiative decay from ...
Quantifying Gene Expression and Regulation in Living Cells by Fluorescence Fluctuation Imaging2017-01-112017-01-11Department of Biochemistry and Molecular Biology , CSU200px200px ...
Fluorophores currently used as fluorescent probes offer sufficient permutations of wavelength range, Stokes shift and spectral bandwidth to meet requirements imposed by instrumentation (e.g., 488 nm excitation), while allowing flexibility in the design of multicolor labeling experiments. Our online Fluorescence SpectraViewer (www.invitrogen.com/handbook/spectraviewer) provides an interactive utility for evaluating these factors during the experimental design process (Using the Fluorescence SpectraViewer-Note 23.1). The fluorescence output of a given dye depends on the efficiency with which it absorbs and emits photons, and its ability to undergo repeated excitation/emission cycles. Absorption and emission efficiencies are most usefully quantified in terms of the molar extinction coefficient (EC) for absorption and the quantum yield (QY) for fluorescence. Both are constants under specific environmental conditions. The value of EC is specified at a single wavelength (usually the absorption ...
The research of biomolecular processes on the level of single molecules and in volume ranges equivalent to the size of a single bacterium is of immense importance, both in basic research and in industrial high-throughput screening. The combination of modern confocal optics, new fluorescent dyes, sensitive photomultipliers and improved data processing has revolutionised the technique of fluorescence correlation spectroscopy (FCS). Over the past few years this has led to its widespread application, and alongside the technological advances in hardware development, Greiner Bio-One worked hand-in-hand with customers and instrument suppliers to develop the glass bottom microplates. These better satisfy the requirements of fluorescence correlation spectroscopy with regard to optical clarity and deformation when compared to standard polystyrene plates ...
We have shown that cold perfusion of hearts generates reactive oxygen and nitrogen species (ROS/RNS). In this study, we determined 1) whether ROS scavenging only during cold perfusion before global ischemia improves mitochondrial and myocardial function, and 2) which ROS leads to compromised cardiac function during ischemia and reperfusion (I/R) injury. Using fluorescence spectrophotometry, we monitored redox balance (NADH and FAD), O(2)(*-) levels and mitochondrial Ca(2+) (m[Ca(2+)]) at the left ventricular wall in 120 guinea pig isolated hearts divided into control (Con), MnTBAP (a superoxide dismutase 2 mimetic), MnTBAP (M) + catalase (C) + glutathione (G) (MCG), C+G (CG), and N(G)-nitro-L-arginine methyl ester (L-NAME; a nitric oxide synthase inhibitor) groups. After an initial period of warm perfusion, hearts were treated with drugs before and after at 27 degrees C. Drugs were washed out before 2 h at 27 degrees C ischemia and 2 h at 37 degrees C reperfusion. We found that on reperfusion the MnTBAP
This review exposes the current poor understanding of the internal segmental chain dynamics of dendrimers in solution probed by monitoring the process of excimer formation between pyrene labels covalently attached to the chain ends of dendrimers. The review begins by covering the bases of fluorescence and the kinetics of pyrene excimer formation before describing a procedure based on the Model Free (MF) analysis that is used to analyze quantitatively the fluorescence decays acquired for dendrimers, the ends of which have been fully and covalently labeled with pyrene. Comparison of the various trends obtained by different research groups describing the efficiency of pyrene excimer formation with the generation number of dendrimers illustrates the lack of consensus between the few studies devoted to the topic. One possible reason for this disagreement might reside in the presence of minute amounts of unattached pyrene labels which act as potent fluorescent impurities and affect the analysis of the
TY - JOUR. T1 - Fluorescence correlation spectroscopy in surface plasmon coupled emission microscope. AU - Borejdo, Julian. AU - Calander, N.. AU - Gryczynski, Zygmunt. AU - Gryczynski, Ignacy. PY - 2006/1/1. Y1 - 2006/1/1. N2 - Study of dynamics of single molecules by Fluorescence Correlation Spectroscopy (PCS) requires that the rate of photon detection per molecule be high, that the background be low, and that there be a large change in fluorescent signal associated with change in a position of a molecule. PCS applied to microscopic Surface Plasmon Coupled Emission (SPCE) suggests a powerful method to meet those requirements. In this method, the observational volume is made shallow by placing a sample on a thin metal film and illuminating it with the laser beam at Surface Plasmon Resonance (SPR) angle through high numerical aperture objective. The illuminating light excites surface plasmons in the metal film that produce an evanescent wave on the aqueous side of the interface. The thickness of ...
Novel core-shell nanoparticles were prepared as encapsulating agents for fluorescent organic dyes. These particles protect the dyes from polar solvents, allowing their use in aqueous environments, such as biological systems. The nanoparticles were synthesized using a ternary surfactant system containing the dyes as templates, using octadecyltrimethoxysilane (OTMS) as a reactive surfactant. Silanol groups were formed by the hydrolysis and condensation of the OTMS methoxy groups, to act as anchoring points for the growth of a siloxane shell. The dyes used in this study are polarity and rigidity sensitive; as a consequence, the dyes emission was studied by steady state fluorescence (SSF) and fluorescent lifetime measurements. The data obtained showed the effects of the isolation of the dyes from the solvent. An increase in the viscosity, together with a decrease in the polarity of the encapsulation volume, produced changes in the emission maxima of the dyes, demonstrating that the dyes were effectively
© The Author(s). Published by IOP Publishing Ltd. Probing the diffusion of molecules has become a routine measurement across the life sciences, chemistry and physics. It provides valuable insights into reaction dynamics, oligomerisation, molecular (re-)organisation or cellular heterogeneities. Fluorescence correlation spectroscopy (FCS) is one of the widely applied techniques to determine diffusion dynamics in two and three dimensions. This technique relies on the temporal autocorrelation of intensity fluctuations but recording these fluctuations has thus far been limited by the detection electronics, which could not efficiently and accurately time-tag photons at high count rates. This has until now restricted the range of measurable dye concentrations, as well as the data quality of the FCS recordings, especially in combination with super-resolution stimulated emission depletion (STED) nanoscopy. Here, we investigate the applicability and reliability of (STED-)FCS at high photon count rates (average
Protein encapsulated gold nanoclusters have received much attention due to the possibility of using them as a non-toxic fluorescent probe or marker for biomedical applications, however one major disadvantage currently is their low brightness and quantum yield in comparison to currently used fluorescent markers. A method of increasing the fluorescence emission of Human Serum Albumin (HSA) encapsulated gold nanoclusters (AuNCs) via a Polyallylamide hydrochloride (PAH) coating is described. PAH molecules with a molecular weight of ~17,500 Da were found to enhance the fluorescence emission of HSA-AuNCs by 3-fold when the protein/polymer concentration ratio is 2:1 in solution. Interestingly, the fluorescence lifetime of the AuNCs was found to decrease while the native tryptophan (TRP) fluorescence lifetime also decreased during the fluorescence emission intensity enhancement caused by the PAH binding. Coinciding with the decrease in fluorescence lifetime, the zeta potential of the system was observed ...
During the past five decades, the use of X-ray analytical methods has increased in the areas of materials characterization and phase identification. The wide range of applicability of the X-ray fluorescence method has made it a technique employed in thousands of laboratories all over the world. Over the years, many techniques and procedures have been developed that greatly enhance the versatility of the method. The purpose of the X-ray clinic is to combine theoretical and practical application of X-ray fluorescence spectrometry ...
Laser-induced fluorescence emission contains information about both spectra and time, so the different shapes, intensities and fluorescent lifetimes of fluorescence emission spectra can be used to measure the categories and contents of fluorescent substances with high sensitivity and good selectivity. To measure the oil micro-contamination in water, we utilized femtosecond ultraviolet laser pulse (fs Laser: MaiTai, Spectra Physics, US) as driving source and gated enhanced type ICCD (Time-resolved Fluorescence Spectroscopy, Lavision, German) as detector. We carried through laser-induced fluorescence measurement on DaGang crude oils and machine oils, accomplished data processing, and analyzed the differences of shapes of fluorescence spectra and lifetimes between crude oil and refined oil ...
Using a confocal epi-illuminated microscope with a polarizing beam splitter and dual-channel detection of single-molecule fluorescence induced by pulsed laser excitation, a new application of the three-dimensional, real-time spectroscopic technique BIFL (burst integrated fluorescence lifetime) is introduced. BIFL allows simultaneous registration of fluorescence intensity, lifetime, and anisotropy. It is shown to be well-suited to identify the freely diffusing fluorescent molecule Rhodamine 123 and the Enhanced Yellow Fluorescent Protein via their characteristic fluorescence anisotropy using a time-resolved analysis. Furthermore, data analysis is discussed and rotational correlation times of single molecules are determined. Applications for multidimensional single-molecule identification are outlined.
The fluorescence properties of tryptophan residues are sensitive to the microenvironment of fluorophores in proteins. Therefore, fluorescence characteristics are widely used to study structural transitions in proteins. However, the decoding of the structural information from spectroscopic data is challenging. Here we present a review of approaches developed for the decomposition of multi-component protein tryptophan fluorescence spectra and correlation of these spectral parameters with protein structural properties.
1. The fluorescent ATP analogue 1,N6-etheno-ATP is a good substrate and an efficient allosteric inhibitor of rabbit skeletal-muscle phosphofructokinase. 2. Fluorescence energy transfer occurs between bound 1,N6-etheno-ATP and phosphofructokinase. 1,N6-Etheno-ATP fluorescence is enhanced, intrinsic protein fluorescence is quenched, and the excitation spectrum of 1,N6-etheno-ATP fluorescence is characteristic of protein absorption. 3. The binding reaction of 1,N6-etheno-ATP observed by stopped-flow fluorimetry is biphasic. The fast phase results from binding to the catalytic site alone. The slow phase results from the allosteric transition of the R conformation into the T conformation induced by the binding of 1,N6-etheno-ATP to the regulatory site. 4. The fluorescence signal that allows the transition of the R conformation into the T conformation to be observed does not arise from 1,N6-etheno-ATP bound to the regulatory site. It arises instead from 1,N6-etheno-ATP bound to the catalytic site as a ...
The ethanol-water mixtures can emit fluorescence when excited by the ultraviolet (UV) light, which is different from pure ethanol and water. There are three emission bands of the mixtures and the center bands are located at 290, 305, and 330 nm, respectively. The fluorescence lifetimes of different emission bands are tested respectively: the average lifetime of 330-nm fluorescence band is about 26.5 ns, for the 305-nm emission band 2.5 ns, and for the 290-nm band 11 ns. By the spectral characteristic and the time-resolved spectroscopy one can conclude that there are several components in the solution of ethanol-water mixture. © 2005 Chinese Optics Letters. PDF Article ...
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TY - JOUR. T1 - Nanosecond fluorescence resonance energy transfer-fluorescence lifetime imaging microscopy to localize the protein interactions in a single living cell. AU - Elangovan, M.. AU - Day, R. N.. AU - Periasamy, A.. PY - 2002/2/18. Y1 - 2002/2/18. N2 - Visualizing and quantifying protein-protein interactions is a recent trend in biomedical imaging. The current advances in fluorescence microscopy, coupled with the development of new fluorescent probes such as green fluorescent proteins, allow fluorescence resonance energy transfer (FRET) to be used to study protein interactions in living specimens. Intensity-based FRET microscopy is limited by spectral bleed-through and fluorophore concentration. Fluorescence lifetime imaging (FLIM) microscopy and lifetime measurements are independent of change in fluorophore concentration or excitation intensity, and the combination of FRET and FLIM provides high spatial (nanometre) and temporal (nanoseconds) resolution. Because only the donor ...
In this work, fluorescence correlation spectroscopy (FCS) was used to investigate the effects of potassium iodide (KI) on the electronic-state population kinetics of a range of organic dyes in the visible wavelength range. Apart from a heavy atom effect promoting intersystem crossing to the triplet states in all dyes, KI was also found to enhance the triplet-state decay rate by a charge-coupled deactivation. This deactivation was only found for dyes with excitation maximum in the blue range, not for those with excitation maxima at wavelengths in the green range or longer. Consequently, under excitation conditions sufficient for triplet state formation, KI can promote the triplet state buildup of one dye and reduce it for another, red-shifted dye. This anticorrelated, spectrally separable response of two different dyes to the presence of one and the same agent may provide a useful readout for biomolecular interaction and microenvironmental monitoring studies. In contrast to the typical notion of ...
Sterile α motif (SAM) domains are found in many different proteins and shown to play important roles in various biological processes. The N-terminal domain of deleted in liver cancer 1 (DLC1) protein is a SAM domain which exists in a monomeric form in aqueous solution and facilitates the distribution of EF1A1 to the membrane periphery and ruffles upon growth factor stimulation. Here, we report the structure of an N-terminal truncated DLC1 SAM domain (DLC1-SAM) and its urea-induced equilibrium unfolding investigated with various biophysical methods such as CD, fluorescence emission spectroscopy, and NMR. CD and tryptophan intrinsic fluorescence emission data imply that the unfolding of DLC1-SAM follows a simple two-state mechanism, yet the NMR data suggest the presence of at least one intermediate state. The intermediate cannot be detected by NMR, but it does not exist in large aggregates as shown by analytical ultracentrifugation experiments. Analysis of the free energy values for different ...
ortho-Aminobenzoic acid (Abz) has been used as a convenient fluorescent donor group in internally quenched fluorescent peptides, which are employed as substrates for several proteolytic enzymes. As Abz is usually bound to the N-amino terminal of these peptides, it is of interest to investigate the Abz group fluorescent properties bound to different amino acids. We report in this article the optical absorption and fluorescent properties, in aqueous media, of Abz bound to the alpha-amino group of Ala, Gly, Leu, ne, Val, Pro, Phe, Arg, Glu, Met, Asn, Tyr, and Trp, with monomethyl-amidated alpha-carboxyl group, in order to explore the origin of the drastic reduction of Abz attached to N-alpha amino group of prolyl-peptides, we also examined the fluorescence properties of Abz-NHCH3, Abz-N(CH3)(2), and Abz-pyrrolidine. Molecular dynamics simulation and NMR data indicated a lack of periplanarity of the Abz-dimethylamide, which could be the origin of low fluorescence quantum yield of ...
Fluorescence spectroscopy is spectroscopy which is based on the analysis of fluorescence light. It can be used in fields like chemistry, medicine and pharmacy, biomedical research and environmental monitoring.
Tryptophan fluorescence quenching is a type of fluorescence spectroscopy used for binding assays. The assay relies on the ability to quench the intrinsic fluorescence of tryptophan residues within a protein that results from changes in the local environment polarity experienced by the tryptophan(s) upon the addition of a binding partner or ligand. The quenching can arise from local changes near the interaction site or from binding-induced conformational changes. In cases where the titrant absorbs at or near the excitation or emission wavelengths of tryptophan, significant quenching can occur even without an interaction. This is known as the inner filter effect. This protocol describes how to use tryptophan fluorescence quenching to investigate the binding affinity of a protein for its partner/ligand and how to check and correct for the inner filter effect. As an example, we measured the binding affinity of the haem-binding protein, HusA, from Porphyromonas gingivalis for haem, and showed how we
Nowadays, emission regulations and the requirement to reduce greenhouse gas emissions have escalated engine development efforts. In the present work, the effect of compression ratio on the performance, combustion and emission characteristics of a spark-ignition engine is evaluated at different opera
合成系列含缩醛的双链正离子类脂分子,并用荧光光谱研究其与牛血清蛋白(BSA)的相互作用.通过荧光的变化,解释蛋白质构象的变化.在低类脂浓度时,少量类脂分子束缚在牛血清蛋白周围,荧光有很大幅度的淬灭,蛋白质本身肽链被解开,与此同时最大发射波长从(344±1) nm 蓝移到(331±1) nm.由于疏水相互作用,更多类脂分子不断地聚集在蛋白质周围,牛血清蛋白中的两个色氨酸残基被完全地包裹在类脂分子形成的双分子膜中,荧光强度不断增加直到恒定不变.;Interactions of a series of dialkyl cationic lipids linking with bovine serum albumin (BSA) through acetal (linker) have been studied by the fluorescence spectroscopy. At low concentrations of cationic lipids, the fluorescence intensity of BSA decreased with binding of cationic lipid, and the maximum of emission wavelength shifted from (344±1)nm to (331±1)nm. It indicates that the BSA goes to uncoiled flexible
PAN, Xiangliang et al. A comparison of five extraction methods for extracellular polymeric substances (EPS) from biofilm by using three-dimensional excitation-emission matrix (3DEEM) fluorescence spectroscopy. Water SA [online]. 2010, vol.36, n.1, pp.111-116. ISSN 1816-7950.. Two physical methods (centrifugation and ultrasonication) and 3 chemical methods (extraction with EDTA, extraction with formaldehyde, and extraction with formaldehyde plus NaOH) for extraction of EPS from alga-bacteria biofilm were assessed. Pretreatment with ultrasound at low intensity doubled the EPS yield without significant modification of the composition of EPS. Extraction with EDTA or extraction with formaldehyde plus NaOH increased yield by about 1 order of magnitude compared with other methods. However, the protein and polysaccharide content in EPS prepared with EDTA or formaldehyde plus NaOH were low. Two fluorescence peaks belonging to protein-like peaks and 2 fluorescence peaks belonging to humic acid-like ...
article{744458, author = {Remaut, Katrien and Sanders, Niek and De Geest, Bruno and Braeckmans, Kevin and Demeester, Jo and De Smedt, Stefaan}, issn = {0927-796X}, journal = {MATERIALS SCIENCE \& ENGINEERING R-REPORTS}, keyword = {SINGLE-PARTICLE TRACKING,FLUORESCENCE CORRELATION SPECTROSCOPY,CROSS-CORRELATION SPECTROSCOPY,advanced light microscopy,nuclear uptake,endocytosis,extracellular matrix,non-viral carriers,gene therapy,GLYCOL-POLYETHYLENIMINE/DNA COMPLEXES,CYSTIC-FIBROSIS SPUTUM,BLOCK-COPOLYMER MICELLES,RESONANCE ENERGY-TRANSFER,CAVEOLAE-MEDIATED ENDOCYTOSIS,INTRAVENOUS GENE DELIVERY,IMAGE CORRELATION SPECTROSCOPY}, language = {eng}, pages = {117--161}, title = {Nucleic acid delivery: Where material sciences and bio-sciences meet}, url = {http://dx.doi.org/10.1016/j.mser.2007.06.001}, volume = {58}, year = {2007 ...
A membrane-based assay device for detecting the presence or quantity of an analyte residing in a test sample is provided. The device utilizes time-resolved fluorescence to detect the signals generated by excited fluorescent labels. Because the labels can have relatively long emission lifetime, short-lived background interference can be practically eliminated through delayed fluorescence detection. In addition, the resulting fluorescent reader can have a simple and inexpensive design. For instance, in one embodiment, the reader can utilize a silicon photodiode and a pulsed light-emitting diode (LED) to accurately excite labels and detect fluorescence on a membrane-based assay device without requiring the use of expensive components, such as monochromators or narrow emission band width optical filters.
Protein-RNA and protein-protein interactions involved in the assembly of the signal recognition particle (SRP) were examined using fluorescence spectroscopy. Fluorescein was covalently attached to the 3′-terminal ribose of SRP RNA following periodate oxidation, and the resulting SRP RNA-Fl was reconstituted into a fluorescent SRP species that was functional in promoting translocation of secretory proteins across the membrane of the endoplasmic reticulum. Each of the two protein heterodimers purified from SRP elicited a substantial change in fluorescein emission upon association with the modified RNA. The binding of SRP9/14 to singly-labeled SRP RNA-Fl increased fluorescein emission intensity by 41% at pH 7.5 and decreased its anisotropy from 0.18 to 0.16. The binding of SRP68/72 increased the fluorescein anisotropy from 0.18 to 0.23 but did not alter the emission intensity of SRP RNA-Fl. These fluorescence changes did not result from a direct interaction between the dye and protein because the ...
A new branch of fluorescence has emerged with the use of metallic nanostructures to enhance optical signals: Plasmon enhanced fluorescence (PEF). In the literature it has grown with two different names: surface enhanced fluorescence (SEF) and also metal enhanced fluorescence (MEF). In this thesis, we have explored some of the peculiar properties of plasmon enhanced fluorescence. In particular, we try to relate intrinsic molecular properties of fluorescence such as cross section and quantum yield to the enhanced signal. The source and basic properties of localized surface plasmon resonances is also discussed. The attention is then centre in the plasmon signature on the fluorescence spectrum or spectral profile modification. The matching of plasmon scattering and fluorescence emission assists in constructing fluorophore-nanoparticle systems for PEF applications. Specific experiments are discussed design to test the impact of the fluorophore quantum yield in observed enhancement. Finally, a practical
We use all-atom MD simulations, combined with patch-clamp electrophysiology and time-resolved fluorescence spectroscopy, to investigate functional dynamics of neurotransmitter transporters and Cl- channels. We developed kinetic state models to explain the functional coupling of secondary active glutamate transport and channel-like anion conduction in EAAT glutamate transporters (1-3), and advanced noise analysis techniques to measure unitary properties of transporter-associated channels (4). Using stopped-flow fluorescence recordings, we identified an induced-fit substrate binding mechanism in EAATs (4). The prokaryotic EAAT homolog GltPh is the founding member of the group of transporters with an elevator transport mechanism, and we used essential dynamics sampling to simulate the inward-outward transition path (5). We identified the Cl- permeation pathway and Cl- conduction mechanism in EAATs (5,6) using Computational Electrophysiology, a simulation technique for all-atom MD simulations of ...
7-AAD Staining Solution is a ready-to-use reagent suitable for the evaluation of cell viability in mono- or multiparametric analyses of human peripheral blood using flow cytometry.7-AAD (7-amino-actinomycin D) is a fluorescent dye that intercalates into double-stranded DNA (GC rich regions). It is excluded from viable cells, but can penetrate cell membranes of dead or dying cells. Therefore, it can be used instead of propidium iodide (PI) for the evaluation of cell death and apoptosis.The fluorescence emission maximum for 7-AAD is at 647 nm. When excited at 488 nm, 7-AAD is detected in the red fluorescence channel commonly used for R-phycoerythrin (PE)-Cy®5 tandem dye detection, with minimal spectral overlap into the yellow fluorescence channel commonly used for PE detection. - Nederland
7-AAD Staining Solution is a ready-to-use reagent suitable for the evaluation of cell viability in mono- or multiparametric analyses of human peripheral blood using flow cytometry. 7-AAD (7-amino-actinomycin D) is a fluorescent dye that intercalates into double-stranded DNA (GC rich regions). It is excluded from viable cells, but can penetrate cell membranes of dead or dying cells. Therefore, it can be used instead of propidium iodide (PI) for the evaluation of cell death and apoptosis. The fluorescence emission maximum for 7-AAD is at 647 nm. When excited at 488 nm, 7-AAD is detected in the red fluorescence channel commonly used for R-phycoerythrin (PE)-Cy® 5 tandem dye detection, with minimal spectral overlap into the yellow fluorescence channel commonly used for PE detection. - Schweiz
Nine novel 2-aryl-6-(aryleneethynylene)-1H-indoles were prepared by one pot Sonogashira cross-coupling in DMSO and fluoride promoted cyclization followed by N-alkylation. The photophysical properties of these compounds are described. Absorption and excitation spectra of these compounds were independent of the solvent polarity, while their emission spectra showed a pronounced dependence. Fluorescence quantum yields in solution were very high and decreased with solvent polarity; possible processes that account for excessive values of ? are discussed. Cyclic voltammetry studies indicate irreversible redox processes and DFT calculations suggest they occur in the indole segment. ...
Thawing permafrost due to increasingly warm temperatures in northern subarctic regions is releasing mercury. The consequent formation of thaw ponds in the peatland palsa valley of the Sasapimakwananisikw (SAS) river in Whapmagoostui-Kuujjuarapik, Québec may provide a pool for MMHg formation and a potential risk to aquatic and human life, if these ponds facilitate MMHg export through hydrological connections to nearby waterways. Hg methylation and MMHg demethylation activities were examined in thaw pond sediments using a Hg tracer isotope incubation experiment. Analysis by coupling gas chromatography cold-vapor atomic fluorescence spectrophotometry (GC-CVAFS) with inductively coupled mass spectrometry (ICP-MS) techniques showed that MMHg was produced at a higher rate and within the first 2 h of incubation for both summer and winter seasons. For thaw ponds SAS1A, SAS1B and SAS2A, MMHg was formed at 0.0048 % h-1, 0.0012 % h-1, and 0.0008 % h-1, respectively during winter and at 0.0001 % h-1, ...
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Fluorescence techniques are being used and applied increasingly in academics and industry. The Principles of Fluorescence Techniques course will outline the basic concepts of fluorescence techniques and the successful utilization of the currently available commercial instrumentation.. The course is designed for students who utilize fluorescence techniques and instrumentation and for researchers and industrial scientists who wish to deepen their knowledge of fluorescence applications. Key scientists in the field will deliver theoretical lectures. The lectures will be complemented by the direct utilization of steady-state and lifetime fluorescence instrumentation and confocal microscopy for FLIM and FFS applications.. Participants are recommended to have at least a bachelors degree in the life sciences, physical sciences or engineering before attending. Interactions between participants and lecturers will be fostered. Students will have ample opportunity to personally explain their research ...
Fluorescence techniques are being used and applied increasingly in academics and industry. The Principles of Fluorescence Techniques course will outline the basic concepts of fluorescence techniques and the successful utilization of the currently available commercial instrumentation.. The course is designed for students who utilize fluorescence techniques and instrumentation and for researchers and industrial scientists who wish to deepen their knowledge of fluorescence applications. Key scientists in the field will deliver theoretical lectures. The lectures will be complemented by the direct utilization of steady-state and lifetime fluorescence instrumentation and confocal microscopy for FLIM and FFS applications.. Participants are recommended to have at least a bachelors degree in the life sciences, physical sciences or engineering before attending. Interactions between participants and lecturers will be fostered. Students will have ample opportunity to personally explain their research ...
Vulnerable plaques, which are responsible for most acute ischemic events, are presently invisible to x-ray angiography. Their primary morphological features include a thin or ulcerated fibrous cap, a large necrotic core, superficial foam cells, and intraplaque hemorrhage. We present evidence that multimodal spectroscopy (MMS), a novel method that combines diffuse reflectance spectroscopy (DRS), intrinsic fluorescence spectroscopy (IFS), and Raman spectroscopy (RS), can detect these markers of plaque vulnerability. To test this concept, we perform an MMS feasibility study on 17 human carotid artery specimens. Following the acquisition of spectra, each specimen is histologically evaluated. Two parameters from DRS, hemoglobin concentration and a scattering parameter, are used to detect intraplaque hemorrhage and foam cells; an IFS parameter that relates to the amount of collagen in the topmost layers of the tissue is used to detect the presence of a thin fibrous cap; and an RS parameter related to ...
While this paper had no mention of wetting, surfaces, or capillary forces, the technique of fluorescence correlation spectroscopy is probably worth mentioning, as it is employed specifically in soft matter experiments. FCS is typically used to measure diffusion constants of fluorescent molecules in solution. The number of fluorescent molecules in the focal spot will follow a Poisson distribution, and the relative change in fluorescence over time with therefore vary both with the number of fluorescent particles (which determines the amplitude of the autocorrelation function) and the rate of diffusion of these particles (which determines the decay rate in the autocorrelation function). So if particles diffuse more slowly, then the fluorescence changes more slowly, and the correlation in fluorescence will apply over longer periods of time. The authors apply this principle of FCS to a two-state system: the MS2-GFP protein, where MS2 is the domain that will bind to a specific RNA target, and GFP is ...
Rapid activation of guanine nucleotide-binding protein (G protein)-mediated signal transduction mechanisms occurs in many tissues. The human neutrophil provides a useful model for studying the mechanisms of these fast processes. Fluorescent chemotactic tetrapeptide and pentapeptide exhibit 30-50% quenching of fluorescence upon binding to the neutrophil formyl peptide receptor, and their binding affinity is strongly regulated by the G protein Gi. We used rapid kinetic spectrofluorometric methods to study the assembly and disassembly of the ternary complex of ligand, receptor, and G protein in digitonin-permeabilized human neutrophils. Binding was studied up to 20 nM ligand, where the half-time for association was 1.2 sec. The rate constant of association was near that for diffusion-limited reactions of ligands and proteins, 2 x 10(7) M-1 sec-1. The rate of uncoupling of formyl peptide receptor from G protein in the presence of high concentrations of guanine nucleotide was , or = 5 sec-1 (i.e., ...
We report the use of the macrocyclic host cucurbit[7]uril (CB7) as a supramolecular additive in nanosecond time-resolved fluorescence (Nano-TRF) assays for proteases to enhance the discrimination of substrates and products and, thereby, the sensitivity. A peptide substrate was labeled with 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) as a long-lived (>300 ns) fluorescent probe and 3-nitrotyrosine was established as a non-fluorescent fluorescence resonance energy transfer (FRET) acceptor that acts as a
Correlation Spectroscopy is an increasingly popular method of analyzing spectral data, with the goal of improved understanding of sample chemistry, physics and spectroscopy. The original form of this method dealt exclusively with cases where a single sample is analyzed spectroscopically while being perturbed mechanically in a sinusoidal manner. However, more recent extensions towards spectroscopic data that is collected in the presence of any sample perturbation led to the concept of Generalized 2D Correlation Spectroscopy, which is the subject of this course.. The course will begin with an explanation of the principles of classical Correlation Spectroscopy. This will include a discussion of the two complementary methods to display the temporal correlation behavior in spectral data sets: the synchronous and asynchronous maps.. Several chemometric methods can be particularly useful when combined with Correlation Spectroscopy, including Self-Modeling Curve Resolution (a series of methods ...
Rothwell, P. J.; Berger, S.; Kensch, O.; Felekyan, S.; Antonik, M.; Woehrl, B. M.; Restle, T.; Goody, R. S.; Seidel, C.: Multiparameter single-molecule fluorescence spectroscopy reveals heterogeneity of HIV-1 reverse transcriptase: primer/template complexes. Proceedings of the National Academy of Sciences of the United States of America 100 (4), S. 1655 - 1660 (2003 ...
The nuclei of embryonic Swiss mouse fibroblasts in culture were targeted with the nucleic acid probe DAPI, which has an excitation maximum at 358 nanometers and an emission maximum at 461 nanometers when bound to DNA in cell cultures and tissue sections.
Because one of the main bottlenecks in determining the structure of protein molecules is producing good isolated single crystals, improved crystallization techniques would be useful in a wide range of genomics and pharmaceutical research.. Research reported in The Journal of Chemical Physics uses fluorescence correlation spectroscopy (FCS) to investigate the processes at the surface of a growing crystal. By focusing a laser on the crystal surface and measuring the resulting fluorescence, FCS can resolve dimensions as small as a single wavelength of the light.. Another advantage of fluorescence is that it provides a high signal-to-noise ratio, says author Shinpei Tanaka of Hiroshima University in Japan. We are able to measure very dilute solutions at the crystal interface.. The researchers found that when single tetragonal crystals of egg-white lysozyme formed, there was no concentration gradient between the solution and the crystal surface. However, in formation of clumps of needle-like ...
This thesis proposes mechanisms by which a spiked mobile phase fluorescence detector (SMP-FD) for HPLC is able to detect not only fluorescent compounds, but non-fluorescent chromophoric and non-fluorescent, non-chromophoric compounds as well. This reconfigured fluorescent detector is achieved simply.... Full description. ...
This thesis proposes mechanisms by which a spiked mobile phase fluorescence detector (SMP-FD) for HPLC is able to detect not only fluorescent compounds, but non-fluorescent chromophoric and non-fluorescent, non-chromophoric compounds as well. This reconfigured fluorescent detector is achieved simply.... Full description. ...
Oligomerization of membrane proteins has received intense research interest because of their importance in cellular signaling and the large pharmacological and clinical potential this offers. Fluorescence imaging methods are emerging as a valid tool to quantify membrane protein oligomerization at high spatial and temporal resolution. Here, we provide a detailed protocol for an image-based method to determine the number and oligomerization state of fluorescently labeled prototypical G-protein-coupled receptors (GPCRs) on the basis of small out-of-equilibrium fluctuations in fluorescence (i.e., molecular brightness) in single cells. The protocol provides a step-by-step procedure that includes instructions for (i) a flexible labeling strategy for the protein of interest (using fluorescent proteins, small self-labeling tags or bio-orthogonal labeling) and the appropriate controls, (ii) performing temporal and spatial brightness image acquisition on a confocal microscope and (iii) analyzing and ...
Fluorescence reading or fluorescence measurement is the measurement of the light rays coming out of the fluorescent particle by energizing through the light at much greater energy and comparatively much lesser wavelength. In this process, a sample is energized through the light generated using a source of light and then screened at a certain wavelength, either using a screener or monochromator.. The samples post being energized mostly radiate the lights at minimal energy and greater wavelength in comparison with the energized light and fluorescence within no time after energizing. The light post emission is screened, captured, and measured as well using detectors. Fluorescence reader comes handy in such occasions.. Energy emission mechanism. Great to see is the way the fluorescence has developed in terms of its standard in the past twenty years. This has made the intensity calculation of fluorescence a highly acclaimed method of fluorescence reader. Making things even more encouraging, there are ...
TY - JOUR. T1 - Synthesis and characterization of membrane stable bis(arylimino)isoindole dyes and their potential application in nano-biotechnology. AU - Kim, Benjamin. AU - Yalaz, Ceren. AU - Pan, Dipanjan. PY - 2012/8/8. Y1 - 2012/8/8. N2 - A synthetic methodology of preparing novel membrane stable, responsive dyes is revealed in this manuscript. 1,3-Bis(arylimino)isoindole dyes were synthesized and their properties to undergo intramolecular hydrogen bonding was studied with fluorescence spectroscopy in varying solvent polarities. Based on the functional moieties, compound that is capable of hydrogen donor and acceptor interactions produces predominant photoexcitation in comparison to the responsive dyes that lack these functionalities. These dyes, by the virtue of the presence of long chain acyl groups could be incorporated stably within the phospholipids membrane of core-shell nanoparticles. Nanoparticle was cracked to release the dye from a hydrophobic to a hydrophilic environment. A ...
Fluorescence Spectrophotometer F-7100Hitachi s Superior Fluorescence Technology has created a new generation of fluorescence spectrometers.F-7100 is the evolution of the robust and reliable F-7000 with the latest optical technology and improved analytical performance. Best-in-Class Analytical Signal-to-Noise Ultra-Fast Scanning 2,500hr Long lifetime light source Compact design Multiple accessoriesWith the highest level for 3D fluorescence spectra, F-7100 can be used in a wide range of applications from the cutting edge research to quality control: Applications.21 CFR Part 11 Compliant software available.
Dianthus instruments are available with a red filterset that can be combined with a multitude of commercially available Fluorophores. Note that it is not necessary for the excitation/emission maximum of a fluorophore to be within the filter windows. Exciting or detecting less than the maximum fluorescence may be sufficient.. ...
... fluorescence, phosphorescence, and luminescence; Raman spectroscopy and FT-Raman; X-ray (XRF, XRD, and microanalysis); mass ... spectrometry; magnetic resonance (NMR, EPR, MRI); surface analysis (ESCA, SIMS, Auger); and laser-based spectroscopic ...
"A LabVIEW-controlled portable x-ray fluorescence spectrometer for the analysis of art objects". X-Ray Spectrometry. 35 (5): ...
"Boot Camp for Conservators Explores X-Ray Fluorescence Spectrometry". The Getty Iris. Retrieved 2019-12-11. van Loon, Annelies ... requires obtaining a sample from an object or artwork and exposing it to X-Ray radiation X-Ray Fluorescence Spectroscopy (XRF) ...
This includes chromatographic techniques coupled to mass spectrometry and fluorescence detectors. All of the chromatographic ... Chromatographic methods with fluorescence detection Liquid chromatography with fluorescence detection (LC-FLD) provides a ... YTX analysis limits of detection of 30 mg/g of shellfish tissue for chromatographic methods coupled to mass spectrometry have ... The techniques used for YTX analysis include: CE with ultraviolet (UV) detection and CE coupled to mass spectrometry (MS). CEUV ...
CS1 maint: discouraged parameter (link) "FIBER OPTICAL ASSEMBLY FOR FLUORESCENCE SPECTROMETRY". United States Patent ... Thus, once deployed for use in a facility, the fluorescence information can be fiberoptically transmitted to a remote location ... The conventional method of performing laser-induced fluorescence, as well as other types of spectroscopic measurements, such as ... increasing the amount of fluorescence signal by around a factor of 10 over conventional apparatus. SOFIA is an apparatus and ...
Deng, C.; Xiong, X.; Krutchinsky, A. N. (2009). "Unifying Fluorescence Microscopy and Mass Spectrometry for Studying Protein ...
Biophysics: calorimetry, CD, fluorescence, light scattering, SPR, ultracentrifugation. Flow Cytometry Fluorescence Activating ... Mass Spectrometry: qualitative, quantitative, and structural analysis of proteins, carbohydrates, oligonucleotides, and lipids ... 2019 Richard M. Caprioli for the discovery of temporal and spatial processing in biological systems using mass spectrometry. ... Mass Spectrometry. 2011 Sir Alec John Jeffreys: Developed techniques for DNA fingerprinting and DNA profiling 2010 Pat Brown: ...
"Investigating the origin and authenticity of Victoria Cross medals using X-ray fluorescence spectrometry". Scientific Reports. ...
... ultra sensitive detection of atoms and molecules using laser Fluorescence and resonance ionization mass spectrometry; the ...
Law for Quantitative X-ray Fluorescence by the Fundamental Parameters Method". X-Ray Spectrometry. 6 (4): 201. Bibcode:1977XRS ... Rene Van Grieken; Andrzej Markowicz (2001). Handbook of X-Ray Spectrometry. CRC Press. p. 3. ISBN 978-0-203-90870-9. Knipp, J.K ...
Law for Quantitative X-ray Fluorescence by the Fundamental Parameters Method". X-Ray Spectrometry. 6 (4): 201. Bibcode:1977XRS ...
The other two systems are the X-ray fluorescence Spectrometry (XRF) and X-ray fluorescence Diffractometry (XRD). The XRF is a ... The collected samples were analyzed for REE and Thorium using X-ray fluorescence (XRF) and Uranium determination using ... Applied Physics Research Section The PNRI houses the Mössbauer Effect Spectrometry (MES) system, which studies nuclear ... In the Radiometric / Gamma ray Spectrometry, gamma ray spectrometers are used for geological mapping, radiogenic mineral ...
In forensic toxicology, techniques involving gas chromatography coupled to mass spectrometry (GC-MS) are the most widely used ... High-performance liquid chromatography (HPLC) is used with ultraviolet, fluorescence, electrochemical, and electrospray mass ... These techniques include ion mobility spectrometry, capillary zone electrophoresis, ultraviolet spectroscopy, and infrared ... psilocybin and psilocin in Psilocybe subcubensis Guzmán by ion mobility spectrometry and gas chromatography-mass spectrometry ...
2005: Gold - JEOL Ltd - DART (direct analysis real-time) ionisation technology for mass spectrometry; Silver - ESA Biosciences ... Portable S2 PICOFOX total reflection X-ray fluorescence spectrometer. 2007: Gold - Waters Corp - Synapt high definition mass ... Full Spectrum Molecular Imaging integrating MALDI, DESI, and ion mobility mass spectrometry techniques and informatics ... Nexera UC fully automated supercritical fluid extraction - supercritical fluid chromatography - mass spectrometry system; ...
Fluorescence polarization immunoassay is widely used. This test is slower and has a lower sensitivity than digoxin immunoassay ... Electrospray Tandem Mass Spectrometry". Journal of Agricultural and Food Chemistry. 53 (11): 4322-5. doi:10.1021/jf050201s. ... Digoxin III). A direct analytic technique like liquid chromatography-electrospray tandem mass spectrometry is used when there ...
... optical emission and x-ray fluorescence (XRF) spectrometry. SPECTRO is a major provider or analytical instrumentation with an ... Instruments is a manufacturer of elemental analyzers using optical emission spectroscopy and x-ray fluorescence spectrometry. ...
Smalley's group employed the use of this method with time-of-flight mass spectrometry by analyzing Al clusters. With the work ... They used laser-induced fluorescence to characterize multiple molecules like SnBi and SiC2. ...
The composition of the coins was later verified using the traditional wet method and X-ray fluorescence spectrometry. ...
Time-resolved fluorescence spectroscopy is an extension of fluorescence spectroscopy. Here, the fluorescence of a sample is ... Time-resolved mass spectrometry Ultrafast laser spectroscopy Wang, L.; Pyle, J. R.; Cimatu, K. A.; Chen, J. (2018). "Ultrafast ... a short laser pulse acts as a gate for the detection of fluorescence light; only fluorescence light that arrives at the ... Stimulated emission follows the fluorescence spectrum of the molecule and is Stokes shifted relative to and often still ...
First the fifty-two sarsens were analysed using methods including x-ray fluorescence spectrometry to determine their chemical ...
Additionally, HPLC, mass spectrometry, and fluorescence spectroscopy can be employed to measure the amount of iso-alpha acids ...
An HPLC method with post-column reaction with alkali and fluorescence has been developed to determine tetrodotoxin and its ... The alkali degradation products can be confirmed as their trimethylsilyl derivatives by gas chromatography/mass spectrometry.[ ...
Light sheet fluorescence microscopy for the observation of development and LILBID mass spectrometry for the analysis of ... Native mass spectrometry has emerged as an important tool in structural biology. Advantages of mass spectrometry compared to ... Using mass spectrometry, a global analysis of the ubiquitinome of Salmonella-infected cells was carried out, that enabled CEF ... Optogenetics and light sheet fluorescence microscopy were selected as the "Method of the Year" across all fields of science and ...
Ultraviolet fluorescence and infrared analysis are used to detect repairs or earlier painting present on canvasses. Atomic ... Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) can be used to analyze the paint-binding medium. Similar to AAS and ... X-ray fluorescence (bathing the object with radiation causes it to emit X-rays) which can reveal if the metals in a metal ... Absorption Spectrophotometry (AAS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are used to detect anomalies in ...
This luciferin fluorescence can be then quantified by spectrometry following a wash, and used to determine the relative ... and fluorescence spectrometry (in which the fluorophore is attached to a target of interest and the target quantified or ... A fluorophore can be attached to one of these probes to give a fluorescence signal upon binding of the reporter molecule to the ... Catalyzed Azide-Alkyne Cycloaddition Directly Observed by Electrospray Ionization Mass Spectrometry". Angewandte Chemie ...
X-ray fluorescence spectroscopy can confirm the presence of bromine (Br), but it does not indicate the BFR concentration or ... Ion attachment mass spectrometry (IAMS) can be used to measure BFR concentrations in plastics. The BFR ban has significantly ... REACH Battery Directive Electronic waste Green computing Ion attachment mass spectrometry - used to enforce RoHS limits on ...
X-ray fluorescence and absorption spectrometry. In 1966 he was appointed Deputy Director of the NPL. He was elected a Fellow of ...
Meanwhile, the taurine-fluorescence-HPLC assay used for cyanide detection is identical to the assay used to detect glutathione ... Cyanide and thiocyanate assays have been run with mass spectrometry (LC/MS/MS), which are considered specific tests. Since ... and the taurine fluorescence-HPLC but like all colorimetric assays these are prone to false positives. Lipid peroxidation ...
... including fluorescence immunoassays, Microscale thermophoresis, FRET, TRF, fluorescence polarization, fluorescence-quenching, ... "Int J Mass Spectrometry. 367: 28-34. Bibcode:2014IJMSp.367...28G. doi:10.1016/j.ijms.2014.04.015. PMC 4375673. PMID 25844054.. ... More recently large-scale mass spectrometry analyses have been used to determine sites of protein phosphorylation. Over the ... However, the analysis of phosphorylated peptides by mass spectrometry is still not as straightforward as for "regular", ...
Chow has used fluorescence spectroscopy and mass spectrometry to study drug-RNA interactions in an effort to inform the design ...
Wikimedia Commons has media related to Fluorescence in situ hybridization.. *Fluorescent+in+Situ+Hybridization at the US ... Fluorescence in situ hybridization (FISH) is a molecular cytogenetic technique that uses fluorescent probes that bind to only ... Fluorescence microscopy can be used to find out where the fluorescent probe is bound to the chromosomes. FISH is often used for ... Fluorescence in situ Hybridization Photos of bacteria. *Rational design of polynucleotide probe mixes to identify particular ...
... pyrene in charcoal grilled meat samples by HPLC with fluorescence detection". Int J Food Sci Nutr. 56 (8): 581-5. doi:10.1080/ ... "Metabolism of Benzo[a]pyrene in Human Bronchoalveolar H358 Cells Using Liquid Chromatography-Mass Spectrometry". Chem. Res. ...
... , or karyopyknosis, is the irreversible condensation of chromatin in the nucleus of a cell undergoing necrosis[1] or apoptosis.[2] It is followed by karyorrhexis, or fragmentation of the nucleus. Pyknosis (from Greek pyknono meaning "to thicken up, to close or to condense") is also observed in the maturation of erythrocytes (a red blood cell) and the neutrophil (a type of white blood cell). The maturing metarubricyte (a stage in RBC maturation) will condense its nucleus before expelling it to become a reticulocyte. The maturing neutrophil will condense its nucleus into several connected lobes that stay in the cell until the end of its cell life. ...
In addition to neutron activation, the laboratory maintains and operates several X-ray fluorescence spectrometers, multiple ICP ... spectrometers, and a multi-collector ICP-MS for isotope-ratio mass spectrometry. The laboratory is one of only a handful of ...
Where a colorant contains fluorescence, a bi-spectral fluorescent spectrophotometer is used. There are two major setups for ... Traditional visible region spectrophotometers cannot detect if a colorant or the base material has fluorescence. This can make ... Inductively coupled plasma mass spectrometry. *LBOZ. *Spectroradiometry. *Slope spectroscopy. *Microspectrophotometry. ...
Mass Spectrometry. Mass spectrometry. Fast atom bombardment. Electron ionization. Chemical ionization. Electrospray ionization ... Fluorescence. Phosphorescence. Jablonski diagram. Emission spectrum. Mie scattering. Beer-Lambert law. Chapter 4. Applied ... Time-of-flight mass spectrometry. Electron multiplier. Faraday cup. Carbon-13. Infrared multiphoton dissociation. Chapter 6. ...
Each spectrum was specific, which is advantageous over fluorescence detection; some fluorescent markers overlap and interfere ... "Mixture analysis and quantitative determination of nitrogen-containing organic molecules by surface-enhanced Raman spectrometry ...
quantitative PCR does not require this, as the detection system uses fluorescence and probes to detect the DNA molecules as ... Electron microscopes and fluorescence microscopes are also used for observing microbes in greater detail for research.[28] ...
Fluorescence, Pigment & Radioactivity. High-throughput technique ("-omics"). DNA microarray. Mass spectrometry. Lab-on-a-chip. ...
Yuste R (December 2005). "Fluorescence microscopy today". Nature Methods. 2 (12): 902-4. doi:10.1038/nmeth1205-902. PMID ... mass spectrometry,[54] which allows rapid high-throughput identification of proteins and sequencing of peptides (most often ... For example, indirect immunofluorescence will allow for fluorescence colocalization and demonstration of location. Fluorescent ...
Isotope-ratio mass spectrometry, Multiple collector - inductively coupled plasma - mass spectrometry (MC-ICP-MS) ... Laser-induced fluorescence. *Laser ablation. *Laser ablation synthesis in solution. *Laser plasma acceleration ...
Sequencing with mass spectrometry[edit]. Mass spectrometry may be used to determine DNA sequences. Matrix-assisted laser ... Following the development of fluorescence-based sequencing methods with a DNA sequencer,[2] DNA sequencing has become easier ... Edwards JR, Ruparel H, Ju J (2005). "Mass-spectrometry DNA sequencing". Mutation Research. 573 (1-2): 3-12. doi:10.1016/j. ... Monforte JA, Becker CH (1 March 1997). "High-throughput DNA analysis by time-of-flight mass spectrometry". Nature Medicine. 3 ( ...
Fluorescence. *Fluorescence anisotropy. Translational Diffusion. *Analytical ultracentrifugation. *Size exclusion ...
In the United States, forensic pathologists typically complete at least one year of additional training (a fellowship) after completing an anatomical pathology residency and having passed the "board" examination administered by The American Board of Pathology or The American Osteopathic Board of Pathology ("board-certified"). Becoming an anatomic pathologist in the United States requires completing a residency in anatomic pathology, which is on-the-job training one must perform upon completing medical school before one may practice unsupervised. Anatomic pathology (as it is called) by itself is a three-year residency. Most U.S. pathologists complete a combined residency in both anatomic and clinical pathology, which requires a total of four years. In the United States, all told, the education after high school is typically 13-15 years in duration (4 years undergraduate training + 4 years medical school + 4-5 years residency [anatomic and clinical pathology combined] + 1-2 year forensic pathology ...
A fluorescence microscope is then used to detect fluorescently labeled antibodies bound to internalized antigens within ... An interesting fact that gas chromatography-mass spectrometry, 16S ribosomal RNA analysis, omics, and other advanced ...
... and Photoluminescence spectrometry. In addition, it is usually considered of extreme importance to find theoretical models that ... X-ray fluorescence (XRF), differential scanning calorimetry (DSC), UV-Vis absorption Spectroscopy, Fourier transform infra-red ...
... by fluorescence in situ hybridization, in Cytogenet. Cell Genet., vol. 57, 2-3, 1991, pp. 109-11, DOI:10.1159/000133124, PMID ... Large-scale mapping of human protein-protein interactions by mass spectrometry (PDF), in Mol. Syst. Biol., vol. 3, 2007, p. 89 ...
Amateur gamma spectrometry of a chunk of a black mold picked in Minamisoma, close to the Fukushima Dai-ichi nuclear plant. ... Cold vapour atomic fluorescence spectroscopy. *Conversion electron mössbauer spectroscopy. *Correlation spectroscopy. *Deep- ... Gilmore G, Hemingway J. Practical Gamma-Ray Spectrometry. John Wiley & Sons, Chichester: 1995, ISBN 0-471-95150-1. ...
DNA damage (or RNA damage in the case of some virus genomes) appears to be a fundamental problem for life. As noted by Haynes,[14] the subunits of DNA are not endowed with any peculiar kind of quantum mechanical stability, and thus DNA is vulnerable to all the "chemical horrors" that might befall any such molecule in a warm aqueous medium. These chemical horrors are DNA damages that include various types of modification of the DNA bases, single- and double-strand breaks, and inter-strand cross-links (see DNA damage (naturally occurring). DNA damages are distinct from mutations although both are errors in the DNA. Whereas DNA damages are abnormal chemical and structural alterations, mutations ordinarily involve the normal four bases in new arrangements. Mutations can be replicated, and thus inherited when the DNA replicates. In contrast, DNA damages are altered structures that cannot, themselves, be replicated. Several different repair processes can remove DNA damages (see chart in DNA repair). ...
2002 - John B. Fenn and Koichi Tanaka for their work on mass spectrometry.[5] Kurt Wüthrich for ways to study biological ... 2014 - Eric Betzig, Stefan Hell and William E. Moerner for the development of super-resolved fluorescence microscopy.[16] ...
How a society responds to diseases is the subject of medical sociology. A condition may be considered a disease in some cultures or eras but not in others. For example, obesity can represent wealth and abundance, and is a status symbol in famine-prone areas and some places hard-hit by HIV/AIDS.[32] Epilepsy is considered a sign of spiritual gifts among the Hmong people.[33] Sickness confers the social legitimization of certain benefits, such as illness benefits, work avoidance, and being looked after by others. The person who is sick takes on a social role called the sick role. A person who responds to a dreaded disease, such as cancer, in a culturally acceptable fashion may be publicly and privately honored with higher social status.[34] In return for these benefits, the sick person is obligated to seek treatment and work to become well once more. As a comparison, consider pregnancy, which is not interpreted as a disease or sickness, even if the mother and baby may both benefit from medical ...
... (from Greek κάρυον karyon, "kernel, seed or nucleus", and ῥῆξις rhexis, "bursting") is the destructive fragmentation of the nucleus of a dying cell[1] whereby its chromatin is distributed irregularly throughout the cytoplasm.[2] It is usually preceded by pyknosis and can occur as a result of either programmed cell death (apoptosis), cellular senescence, or necrosis. In apoptosis, the cleavage of DNA is done by Ca2+ and Mg2+ -dependent endonucleases. ...
Pyrolysis mass spectrometry later identified the deposit as polymethylcyanoacrylaon of Boin crystal parameters.[165] ... Fluorescence. *Fluorescence anisotropy. Translational Diffusion. *Analytical ultracentrifugation. *Size exclusion ...
Mg2+ chelators lag behind and the major fluorescence dye for Mg2+ (mag-fura 2[59]) actually has a higher affinity for Ca2+.[60] ... Inductively coupled plasma (ICP) using either the mass spectrometry (MS) or atomic emission spectroscopy (AES) modifications ... A number of chelators of divalent cations have different fluorescence spectra in the bound and unbound states.[58] Chelators ... "Development and Use of Chlorotetracycline Fluorescence as a Measurement Assay of Chloroplast Envelope-Bound Mg2+". Plant ...
Zn(II) binding increases fluorescence intensity, while Cu(II) binding quenches fluorescence and shifts the absorbance maximum ... Peptide mass fingerprinting/Protein mass spectrometry. *Dual-polarization interferometry. *Microscale thermophoresis. * ... The fluorescence quantum yield (QY) of GFP is 0.79. The GFP from the sea pansy (Renilla reniformis) has a single major ... EGFP has an extinction coefficient (denoted ε) of 55,000 M−1cm−1.[19] The fluorescence quantum yield (QY) of EGFP is 0.60. The ...
2/Ar ratio measurements by membrane inlet mass spectrometry". Geophys. Res. Lett. 32 (19): n/a. Bibcode:2005GeoRL..3219605K. ... fluorescence kinetics (technique still a research topic). *Stable isotopes of Carbon (12C and 13C)[18] ... or a membrane inlet mass spectrometry (MIMS).[21] However, if results relevant to the carbon cycle are desired, it is probably ... "Continuous high-frequency dissolved O2/Ar measurements by equilibrator inlet mass spectrometry". Anal. Chem. 81 (5): 1855-1864 ...
Chromosomal localization of the human histone H2A.X gene to 11q23.2-q23.3 by fluorescence in situ hybridization. . In: Hum. ... Residue-specific mass signatures for the efficient detection of protein modifications by mass spectrometry. . In: Anal. Chem. ...
Main article: Ion-mobility spectrometry-mass spectrometry. Ion mobility spectrometry-mass spectrometry (IMS/MS or IMMS) is a ... accelerator mass spectrometry (AMS), thermal ionization-mass spectrometry (TIMS) and spark source mass spectrometry (SSMS). ... Photoionization mass spectrometry[edit]. Photoionization can be used in experiments which seek to use mass spectrometry as a ... Preparative mass spectrometry[edit]. The primary function of mass spectrometry is as a tool for chemical analyses based on ...
Fluorescence. *Fluorescence anisotropy. Translational Diffusion. *Analytical ultracentrifugation. *Size exclusion ...
INTERNATIONAL ATOMIC ENERGY AGENCY, Radioisotope X Ray Fluorescence Spectrometry, Technical Reports Series No. 115, IAEA, ...
ICDD X-ray Fluorescence Clinic. Practical X-ray Fluorescence. History of the Clinic The ICDD X-ray Clinics are a continuation ... The purpose of the X-ray clinic is to combine theoretical and practical application of X-ray fluorescence spectrometry. ... The wide range of applicability of the X-ray fluorescence method has made it a technique employed in thousands of laboratories ...
Get the latest energy dispersive x-ray fluorescence spectrometry news , the worlds largest environmental industry marketplace ... energy dispersive x-ray fluorescence spectrometry News. Related terms for "energy dispersive x-ray fluorescence spectrometry ... The performance and accuracy of energy dispersive X-ray fluorescence (ED-XRF) spectrometry performing elemental analysis in the ... spectrometry using multiple monochromatic excitation beams - also known as High-Definition X-ray Fluorescence (HDXRF). With a ...
Posted: Wed 29 Aug, 2018 6:09 pm Post subject: X-Ray Fluorescence Spectrometry (XRF) Results - 4 Swords. ... Forum Index , Historical Arms Talk , X-Ray Fluorescence Spectrometry (XRF) Results - 4 Swords ... Forum Index , Historical Arms Talk , X-Ray Fluorescence Spectrometry (XRF) Results - 4 Swords. ... examined with a PV 9800 X-ray fluorescence spectrometer. In result of the chemical analysis the following composition of the ...
Abstract: Time-resolved fluorescence measurements reveal intermolecular interactions depending upon the... ... Home » Publications Technical Journal "Readout" Article » Importance of and Features in Time-Resolved Fluorescence Spectrometry ... Abstract: Time-resolved fluorescence measurements reveal intermolecular interactions depending upon the environment of the ... This paper describes the basic background and some examples of how the fluorescence lifetime is more informative than steady- ...
... was used as a complimentary detection system for time-of-flight ion mobility spectrometry (TOF-IMS). A LIF detection system is ... A laser-induced fluorescence (LIF) was used as a complimentary detection system for time-of-flight ion mobility spectrometry ( ... Ion mobility spectrometry (IMS) Laser-induced fluorescence (LIF) Electrospray ionization (ESI) Xanthene dye Rhodamine ... Frankevich V, Martinez-Lozano Sinues P, Barylyuk K, Zenobi R. Ion mobility spectrometry coupled to laser-induced fluorescence. ...
Once the Wireless Spectrometer is attached to a computing device running the Spectrometry software,... ... Once the Wireless Spectrometer is attached to a computing device running the Spectrometry software, you will be able to select ... the full spectrum illumination (Absorbance/Transmittance Tab), 405 nm (Fluorescence (405 nm), or 500 nm (Fluorescence (500nm)) ...
Unifying Fluorescence Microscopy and Mass Spectrometry for Studying Protein Complexes in Cells. Changhui Deng, Xinghua Xiong ... Combined Fluorescence Microscopy and Mass Spectrometry Experiment. A schematic diagram of the combined microscopy/mass ... We have combined fluorescence microscopy and mass spectrometry techniques for studying the composition and dynamic properties ... The schematic diagram of the combined fluorescence microscopy and mass spectrometry experiment. After the cells are grown and ...
Atomic Fluorescence Spectroscopy Analyzers *LUMINA 3500 Atomic Fluorescence Spectrometer. *LUMINA 3400 Atomic Fluorescence ... Atomic Fluorescence Spectroscopy Analyzers *LUMINA 3500 Atomic Fluorescence Spectrometer. *LUMINA 3400 Atomic Fluorescence ... Atomic Fluorescence Spectrometry (AFS) is an analytical technique that is primarily used to detect and quantify metals. It is ... One of the great benefits of the Auroras LUMINA Atomic Fluorescence Spectroscopy instrumentation is the incorporation of a ...
X-ray fluorescence spectrometry characteristics of oily waste water from steel processing and an evaluation of its impact on ... The x-ray fluorescence analysis showed that the concentrations of elements, such as silicon, calcium, iron, and zinc, were ...
It is shown that fluorescence line-narrowing spectroscopy (FLNS) is a rapid, versatile, highly sensitive and selective ...
... in coal ash were determined by energy-dispersive X-ray fluorescence spectrometry; major elements (Na, Mg, Al, Si, P, S, K, Ca, ... in whole coal were determined by wavelength-dispersive X-ray fluorescence spectrometry. The results of this study will be used ... X-ray fluorescence spectrometric methods were used in the analysis of eight Argonne Premium Coal Samples. Trace elements (Cr, ... Analysis of eight argonne premium coal samples by X-ray fluorescence spectrometry. Energy & Fuels By:. J.R. Evans , G.A. ...
X-Ray Fluorescence Spectrometry (XRF) in Geoarchaeology - Author: Shackley, M. Steven - Price: 111,60€ ... X-Ray Fluorescence Spectrometry (XRF) in Geoarchaeology. 111,60€. Add to cart. Ebook, PDF with Adobe DRM. ISBN: 9781441968869. ... 1. X-Ray Fluorescence Spectrometry in Twenty-First Century Archaeology. M. Steven Shackley. 2. An Introduction to X-Ray ... 3. Factors Affecting the Energy-Dispersive X-Ray Fluorescence (EDXRF) Analysis of Archaeological Obsidian. M. Kathleen Davis, ...
X-Ray Fluorescence Spectrometry (XRF) in Geoarchaeology by M. Steven Shackley and Publisher Springer. Save up to 80% by ... X-Ray Fluorescence Spectrometry (XRF) in Geoarchaeology by M. Steven Shackley and Publisher Springer. Save up to 80% by ... X-Ray Fluorescence Spectrometry (XRF) in Geoarchaeology by M. Steven Shackley and Publisher Springer. Save up to 80% by ...
The major reasons for more usage of molecular fluorescence spectrometry in comparison to molecular phosphorescence spectrometry ... The major reasons for more usage of molecular fluorescence spectrometry in comparison to molecular phosphorescence spectrometry ... Phosphorescence spectrometry is closely related to fluorescence. The transition from excited to ground state takes time in this ... Concept introduction: Phosphorescence spectrometry is closely related to fluorescence. The transition from excited to ground ...
... Vehus, ... We propose a method which combines liquid chromatography (LC) in three orthogonal dimensions together with fluorescence ... polarization (FP) and mass spectrometry (MS) to identify target proteins in complex mixtures. Results show that FP applied on ...
The use of field-portable X-ray fluorescence (FPXRF) to do detailed surveying, with limited laboratory confirmation, can ... Lead in soil by field-portable x-ray fluorescence spectrometry - an examination of paired In Situ and laboratory ICP-AES ... Lead in soil by field-portable x-ray fluorescence spectrometry - an examination of paired In Situ and laboratory ICP-AES ... 2008). Lead in soil by field-portable x-ray fluorescence spectrometry - an examination of paired In Situ and laboratory ICP-AES ...
X-ray fluorescence. X-ray fluorescence (XRF) spectroscopy is one of the simplest and most widely used techniques for the non- ... Grazing incidence X-ray fluorescence (GIXRF). One of the variants of TXRF, often referred as fluorescence-assisted X-ray ... "Sample preparation for evaluation of detection limits in X-ray fluorescence spectrometry", Anal. Sci. 21, 143-147 (2005). doi: ... By comparing Figures 4(d) and 4(e), it can be seen that the Au-La fluorescence yield shows strong variations below qC, when the ...
... which is main component of antifouling paint of ships on molecular level was investigated by fluorescence spectrometry for ... Results revealed that fluorescence quenching arose mainly from static quenching by complex formation when DBT/HAS less than 3. ... Micro-region of tryptophan residues and tyrosine residues which contribute intrinsic fluorescence to HAS is appreciably ... Bonding Mechanism of Dibutyltin with Human Serum Albumin by Fluorescence Spectrometry. SUN Xiao-lei, LIU Dan (School of ...
... eng. ... 2001 Validation of X-Ray Fluorescence-Measured Swine Femur Lead Against Atomic Absorption Spectrometry. Environmental Health ... Validation of X-Ray Fluorescence-Measured Swine Femur Lead Against Atomic Absorption Spectrometry. URI. http://hdl.handle.net/ ... The aim of this study was to apply the technique of 109Cd-based K-shell X-ray fluorescence (XRF) bone lead measurements to ...
Fluorescence by Selective Pressure Incorporation of Non-canonical Amino Acids and Protein Analysis by Mass Spectrometry and ... Fluorescence by Selective Pressure Incorporation of Non-canonical Amino Acids and Protein Analysis by Mass Spectrometry and ... Fluorescence by Selective Pressure Incorporation of Non-canonical Amino Acids and Protein Analysis by Mass Spectrometry and ... Mass Spectrometry equipment. mass spectrometer for LC-ESI-TOF-MS. Agilent. Agilent 6530 Accurate-Mass QTOF. coupled with ...
Fluorescence by Selective Pressure Incorporation of Non-canonical Amino Acids and Protein Analysis by Mass Spectrometry and ... Mass Spectrometry equipment. mass spectrometer for LC-ESI-TOF-MS. Agilent. Agilent 6530 Accurate-Mass QTOF. coupled with ... fluorescence decay data analysis software. Picoquant GmbH. FluoFit program. data analysis software. OriginLab Inc.. Origin 9.2 ... Pelet, S., Previte, M. J. R., Laiho, L. H., So, P. T. C. A fast global fitting algorithm for fluorescence lifetime imaging ...
... edible alga samples by microwave-assisted extraction and high performance liquid chromatography coupled to atomic fluorescence ... samples by microwave-assisted extraction and high performance liquid chromatography coupled to atomic fluorescence spectrometry ... Total arsenic concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) after ... by high performance liquid chromatography-ultraviolet photo-oxidation-hydride generation atomic-fluorescence spectrometry (HPLC ...
Routine method for analysis of high alloy steel by X-ray fluorescence spectrometry (XRF) by using a near by technique Status : ... Routine method for analysis of high alloy steel by X-ray fluorescence spectrometry (XRF) by using a near by technique. ... Determination of main constituents and impurities by wavelength dispersive X-ray fluorescence spectrometry (XRF). Guidelines to ... Method for multi-element analysis by wavelength dispersive X-ray fluorescence * 20/30408871 DC BS ISO 11433. Nickel alloys. ...
Determination of Arsenic in Lead-based Alloy Using Hydride Generation-Atomic Fluorescence Spectrometry. ... A Novel Hydride Generation System for the Simultaneous Determination of Lead and Cadmium Using Atomic Fluorescence Spectrometry ... APPLICATION OF PULSED HOLLOW-CATHODE LAMP IN HYDRIDE GENERATION NON-DISPERSIVE ATOMIC FLUORESCENCE SPECTROMETRY[J];Chinese ... Strontium and Calcium in Metal Alloy Lead by Inductively Coupled Plasma Atomic Emission Spectrometry[J];Analysis and Testing ...
Fluorescence Microscopy. Фармацевтика. Разработка новых лекарственных препаратов. Drug Development. Drug Manufacturing. ... Fluorescence Microscopes. Ultima Multiphoton Microscopy. Opterra Confocal Microscopy. Vutara Super-Resolution Microscopy. ... Mass Spectrometry. LabScape - Magnetic Resonance & Preclinical Imaging. IR,NIR & Raman. Рентгеновская дифракция и элементный ...
Detection of Alkynes via Click Chemistry with a Brominated Coumarin Azide by Simultaneous Fluorescence and Isotopic Signatures ... click-chemistry products form novel brominated coumarin azide tag alkyne mass spectrometry Brominated Coumarin Azide Mass ... possess distinct intrinsic properties that can be used for their facile detection by either fluorescence or mass spectrometry. ... via Click Chemistry with a Brominated Coumarin Azide by Simultaneous Fluorescence and Isotopic Signatures in Mass Spectrometry ...
... comparison with mass spectrometry quantification. Accueil › Quantitative fluorescence spectroscopy and flow cytometry analyses ... To study the internalization of CPPs /PTDs, fluorescence-based techniques, such as flow cytometry or fluorescence microscopy ... Quantitative fluorescence spectroscopy and flow cytometry analyses of cell-penetrating peptides internalization pathways: ... Quantitative fluorescence spectroscopy and flow cytometry analyses of cell-penetrating peptides internalization pathways: ...
A study using electrospray ionization mass spectrometry and fluorescence binding studies. Journal of Biological Chemistry, 277 ... Fluorescence binding studies show that the apical domain can fully bind both peptides independently. No competition for binding ...
  • The presence of eleven arsenic species was studied by high performance liquid chromatography-ultraviolet photo-oxidation-hydride generation atomic-fluorescence spectrometry (HPLC-(UV)-HG-AFS) developed methods, using both anion and cation exchange chromatography. (universia.net)
  • The histamine/OPD derivative was isolated from zymogen stimulated and untreated leukocyte cultures and analyzed by high performance liquid chromatography with fluorescence analysis. (cdc.gov)
  • Many technologies have been developed for the measurement of this protein adduct including immunoassays, high-performance liquid chromatography (HPLC) with fluorescence detection, and a newly developed isotope-dilution mass spectrometry method. (aacrjournals.org)
  • To address this issue, 19 human serum samples that had been previously analyzed for the aflatoxin B 1 -lysine adduct by high-performance liquid chromatography-fluorescence in 1989 were re-analyzed by isotope dilution mass spectrometry after storage at −80°C. The adduct concentrations measured by these two techniques were identical within 4% over the range 5 to 100 pg of aflatoxin B 1 -lysine/mg albumin. (aacrjournals.org)
  • Immunoassays, high-performance liquid chromatography (HPLC) with fluorescence detection, and isotope dilution mass spectrometry (IDMS) have been used to measure serum albumin adduct concentrations and assess aflatoxin exposure status in epidemiologic studies ( 9 - 12 ). (aacrjournals.org)
  • The department has several HPLC instruments including an Agilent 1220 HPLC system with diode array UV detector and fluorescence detector. (stthomas.edu)
  • Aflatoxin-albumin adduct concentrations measured by ELISA are well correlated with AFB 1 -lys concentrations measured by HPLC-fluorescence and IDMS, albeit the levels obtained in a recent study found that values using an ELISA were 2.6-fold higher than those measured in the same samples by IDMS ( 12 , 13 ). (aacrjournals.org)
  • Furthermore, we have explored the question of the long-term stability of this protein adduct in stored samples, in which the concentrations had been determined using HPLC with fluorescence detection ( 11 ). (aacrjournals.org)
  • Analyses were also conducted by HPLC with fluorescence detection. (cdc.gov)
  • Particulate PAHs were Soxhlet extracted with cyclohexane and analyzed by HPLC with fluorescence detection. (cdc.gov)
  • HPLC of incubate identified only one NADPH-dependent metabolite, which had a chromatographic retention time and UV absorbance, fluorescence, and mass spectra that were identical with authentic 4-hydroxypropofol standard. (aspetjournals.org)
  • HPLC with fluorescence detection provided a highly sensitive quantitation method for 4-hydroxypropofol with a quantitation limit of 8 ng/ml using optimized excitation/emission wavelengths (288 nm/330 nm, respectively). (aspetjournals.org)
  • As a first step in substantiating this hypothesis, we have developed and validated an in vitro propofol hydroxylation system, which incorporates a novel and highly sensitive 4-hydroxypropofol assay using HPLC with fluorescence detection. (aspetjournals.org)
  • Christensen, LH & Agerbo, A 1981, ' Determination of Sulfur and Heavy Metals in Crude Oil and Petroleum Products by Energy-Dispersive X-Ray Fluorescence Spectrometry and Fundamental Parameter Approach ', Analytical Chemistry , vol. 53, no. 12, pp. 1788-1792. (dtu.dk)
  • Energy-dispersive X-ray fluorescence spectrometry (EDXRF) is a well-established analytical technique successfully applied with good precision and accuracy to determination of many elements. (scribd.com)
  • A laser-induced fluorescence (LIF) was used as a complimentary detection system for time-of-flight ion mobility spectrometry (TOF-IMS). (springer.com)
  • Time resolved laser-induced fluorescence of electrosprayed ions confined in a linear quadrupole trap. (springer.com)
  • Frankevich V, Martinez-Lozano Sinues P, Barylyuk K, Zenobi R. Ion mobility spectrometry coupled to laser-induced fluorescence. (springer.com)
  • Frankevich VE, Barylyuk KV, Martinez-Lozano Sinues P, Zenobi R. Ion mobility spectrometry coupled to laser-induced fluorescence for probing the electronic structure and conformation of gas-phase ions. (springer.com)
  • Airborne intercomparison of HOx measurements using laser-induced fluorescence. (nasa.gov)
  • Thus, in addition to several excellent chapters on laser fundamentals, there are many practically oriented artic1es dealing with laser analytical methodology, inc1uding techniques based on the absorption oflaser radiation, on laser-induced fluorescence, and on some of the uses of lasers in chemical instru- mentation. (springer.com)
  • We have developed and applied a method unifying fluorescence microscopy and mass spectrometry for studying spatial and temporal properties of proteins and protein complexes in yeast cells. (mcponline.org)
  • Our results indicate that this approach combining fluorescence microscopy and mass spectrometry into a single method provides a unique perspective into molecular mechanisms regulating composition and dynamic properties of the protein complexes in living cells. (mcponline.org)
  • Combined with genetics and molecular biology techniques fluorescence microscopy provides an efficient tool for observing molecular phenotypes useful for dissecting the pathways of cell cycle progression and cell response to internal and external signals ( 7 ). (mcponline.org)
  • In this case we can decouple requirements for both modules and optimize the performance of each one independently for fluorescence microscopy and affinity purification experiments. (mcponline.org)
  • To study the internalization of CPPs /PTDs, fluorescence-based techniques, such as flow cytometry or fluorescence microscopy imaging are predominant in the litterature. (ens.fr)
  • Such methods are particularly used in fluorescence microscopy e.g. for biological research, where certain structures within biological cells can be marked. (rp-photonics.com)
  • In vitro LA-ICP-MS imaging ( 165 Ho) enabled clear discrimination between CXCR4 positive and negative cells, but fluorescence microscopy was required to determine the intracellular distribution. (nih.gov)
  • Stefan Hell and colleagues propose that the use of pulsed excitation with a delay of at least one microsecond between pulses can dramatically reduce photobleaching and increase the effective fluorescence signal in both single and multi-photon fluorescence microscopy. (nature.com)
  • This allows fluorescence measurements of specified ions and ion clusters, which would not survive in a mass spectrometer. (springer.com)
  • Gas-phase fluorescence excitation and emission spectroscopy of three xanthene dyes (rhodamine 575, rhodamine 590 and rhodamine 6G) in a quadrupole ion trap mass spectrometer. (springer.com)
  • The FL 6500 Fluorescence Spectrometer is the optimal system for analysing samples susceptible to photo-bleaching. (monash.edu.my)
  • ID: CMO:0000280 Synonyms: 2.7 The Hg passes into an inert gas stream that carries the released Hg(0) into the cell of a cold-vapor atomic fluorescence spectrometer (CVAFS) for detection. (progettovoce.com)
  • Part science fair, part hard-core science: Middle school student Camille Weindorf scans soil samples with a portable x-ray fluorescence (PXRF) spectrometer mounted in a hooded test stand. (photonics.com)
  • Although most instruments that detect fluorescence use an expensive and delicate spectrometer, the researcher team used an inexpensive and simple setup of four photodiode detectors with different colors of cellophane film filters. (azooptics.com)
  • When used together, these create a comprehensive fluorescence spectrometer solution for research and commercial laboratories to handle a variety of application challenges. (labmate-online.com)
  • The FL 8500 fluorescence spectrometer uses a high performance Xenon continuous wave excitation source with PerkinElmer optics for high sensitivity measurements, at scan speeds up to 60,000 nanometers. (labmate-online.com)
  • The FL 6500 fluorescence spectrometer, which uses PerkinElmer optics and a Xenon pulse excitation source with variable power settings, is designed for testing samples that are susceptible to photo bleaching. (labmate-online.com)
  • Figure 6 Polarized excitation and fluorescence detection. (horiba.com)
  • A LIF detection system is potentially faster than a conventional electrometer detector and can provide additional (to usual for IMS drift time) analytical information, namely wavelength of fluorescence maxima and fluorescence lifetime. (springer.com)
  • The obtained results are promising enough to ensure the potential of LIF as a complimentary/alternative detection system for time-of-flight ion mobility spectrometry. (springer.com)
  • However, challenges still exist for detecting alkynes because most 1,2,3-triazole products from alkynes and azides do not possess distinct intrinsic properties that can be used for their facile detection by either fluorescence or mass spectrometry. (figshare.com)
  • For the total organic mercury determination, the organic extract is analysed for â totalâ mercury after nitric acid/peroxide digestion, evaporation of the solvent and detection by cold vapour-atomic fluorescence spectrometry. (progettovoce.com)
  • A detection limit of 6 ng lâ 1, * Once separated, both species are converted to Hg0 on-line and quantified by cold-vapor atomic fluorescence spectrometry (CVAFS). (progettovoce.com)
  • The optimization of the polymer/tracer/detection system is based on several criteria: the reliability and speed of detection of UV fluorescence tracers added to a polymer matrix with carbon black, the relevance of the environmental impact of the tracers, and the preservation of the mechanical properties of the polymer with the tracers added. (ensam.eu)
  • A description of a new technology for automatic sorting of plastics, based on X-ray fluorescence detection of tracers, added in such materials is presented. (ensam.eu)
  • This study focused on the detection of rare earth oxides, used as tracers for the identification of polymer materials, using XRF (X-ray fluorescence) spectrometry. (ensam.eu)
  • The assay format, termed SAMDI-MS (self-assembled monolayers for matrix assisted laser desorption ionization time-of-flight mass spectrometry), is based on the enzymatic modification of peptides immobilized to monolayer substrates, followed by direct detection of the products with mass spectrometry. (northwestern.edu)
  • Providing an exhaustive review of this topic, Inorganic Mass Spectrometry: Principles and Applications provides details on all aspects of inorganic mass spectrometry, from a historical overview of the topic to the principles and functions of mass separation and ion detection systems. (wiley.com)
  • Fluorescence of other biological samples can be brought about by chemical treatment to make their detection easier. (encyclopedia.com)
  • 1992) have demonstrated the full power of capillary GC using both mass spectrometry (MS) and flame ionization detection (FID) for analyzing coal tar. (cdc.gov)
  • The headspace vapors are analyzed using GC-mass spectrometry (MS), which provides a detection sensitivity of between 1 and 5 nM (0.056 and 0.28 g/L) acrolein in urine. (cdc.gov)
  • Methods @#The effect of mobile phase about chromatography separation and sample pretreatment conditions and atomic fluorescence spectrometry detection parameters has been optimized to reliably measure the following four kinds of species arsenic compound including arsenic [As (III) ]、 dimethylarsinic acid (DMA) 、monomethylarsonic acid (MMA) and arsenate[As (V) ] in acute intoxication human blood . (bvsalud.org)
  • Total reflection X-ray fluorescence spectrometry (TXRF) is a well-established method for trace element analysis on a variety of samples. (bruker.com)
  • The compact and portable X-ray fluorescence solution for reliable non-contact and non-destructive elemental analysis of valuable objects. (bruker.com)
  • This book brings together the knowledge and expertise of internationally recognised scientists with practical experience of in situ analysis using portable X-ray fluorescence technology. (rsc.org)
  • Her Portable X ray Fluorescence Spectrometry Capabilities for In consists the theories and papers of proposing the model, from Providing whether platform has the maritime oflandslide to involving a true amount for Not making the free l. (fussball-und-wetten.de)
  • Dworkin was that this different Portable X ray Fluorescence Spectrometry Capabilities for In Situ would be to several impact and the strategy of magnificent book and Business. (fussball-und-wetten.de)
  • The available Portable X ray Fluorescence Spectrometry Capabilities for In Situ is the bottom of an sudden Israel juice that is imposed the US Congress into its j. rich cookies on the F. In Everyone, Israel has not a artesian crisis of perforated political behaviour, and most of that was applied in the US to the plate of the important homelessness. (fussball-und-wetten.de)
  • weiter This Portable X ray Fluorescence Spectrometry Capabilities for lets applicable icon and Ancient days for gap attempts in the third plants in Jordan and Many fisheries. (fussball-und-wetten.de)
  • The technique, known as portable x-ray fluorescence spectrometry (PXRF), was used to determine the calcium (Ca) concentration of 75 soil samples from four U.S. states. (photonics.com)
  • contained in this article in third party publications Cold Vapor Atomic Fluorescence Spectrometry - How is Cold Vapor Atomic Fluorescence Spectrometry abbreviated? (tps-dp.com.ua)
  • Cold Vapor Atomic Fluorescence Spectrometry listed as CVAFS. (tps-dp.com.ua)
  • Cold Vapor Atomic Fluorescence Spectrometry (CV-AFS) EPA Method 1631 Manual Method 2009 International Water Conference 12. (tps-dp.com.ua)
  • Cold Vapor Atomic Fluorescence Spectrometry (CV-AFS) EPA Method 1631 Why use CV-AFS? (tps-dp.com.ua)
  • https://en.m.wikipedia.org/wiki/Cold_vapour_atomic_fluorescence_spectroscopy The primary techniques for mercury analysis species are converted to Hg0 on-line and quantified by cold-vapor atomic spectroscopy! (tps-dp.com.ua)
  • The QuickTrace® M-8000 Cold Vapor Atomic Fluorescence (CVAF) Mercury Analyzer is ideal for ultra-trace to sub-mg/L mercury quantitation. (progettovoce.com)
  • Hg) in filtered and unfiltered water by distillation, aqueous ethylation, purge and trap, desorption, and cold vapor atomic fluorescence spectrometry (CVAFS). (progettovoce.com)
  • CVAFS - Cold Vapor Atomic Fluorescence Spectrometry. (progettovoce.com)
  • The aim of this study was to apply the technique of 109Cd-based K-shell X-ray fluorescence (XRF) bone lead measurements to swine femurs and to validate the concentrations obtained therefrom against an independent chemical measurement of bone lead: atomic absorption spectrometry (AAS). (umsystem.edu)
  • Todd AC, Moshier EL, Carroll S, Casteel SW, 2001 Validation of X-Ray Fluorescence-Measured Swine Femur Lead Against Atomic Absorption Spectrometry. (umsystem.edu)
  • to reproduce figures, diagrams etc. atomic spectrometry or cold-vapour atomic fluorescence spectrometry 1 Scope This horizontal standard specifies a method for the determination of mercury in nitric acid digest or aqua regia extract, with cold-vapour atomic absorption spectrometry method or cold-vapour atomic fluorescence spectrometryâ ¦ Your browser does not support JavaScript. (tps-dp.com.ua)
  • Mod-04 Lec-26 Electrothermal Atomic Absorption Spectrometry â ¦ With an accout for my.chemeurope.com you can always see everything at a glance - and you can configure your own website and individual newsletter. (tps-dp.com.ua)
  • Samples are analysed using either cold vapour atomic absorption spectrometry (CVAAS) or cold vapour atomic fluorescence spectrometry (CVAFS) after acid dissolution of the mercury collected. (tps-dp.com.ua)
  • Mod-04 Lec-26 Electrothermal Atomic Absorption Spectrometry â ¦ You do not have JavaScript enabled. (progettovoce.com)
  • Depending of the type of sample to be analyzed, and the performance level being sought, in the laboratory, absorption spectrometry is used either on molecules in liquid or gaseous phase, or on atomic vapor, obtained through thermal breakdown of liquid or solid samples. (ukessays.com)
  • Near-infrared optical absorption spectrometry and fluorescence emission measurements are used to determine gas-fraction concentrations and to identify fluid types, respectively, as fluids flow through the CFA module. (slb.com)
  • This makes this method one of the most sensitive atomization methods available not only for AFS, but also other trace-metal focused elemental analysis procedures, such as Atomic Absorbance Spectrometry (AAS). (aurorabiomed.com)
  • X-ray fluorescence spectrometric methods were used in the analysis of eight Argonne Premium Coal Samples. (usgs.gov)
  • The short course is a tightly integrated two-week course on the fundamentals, instrumentation, qualitative analysis, sample preparation, quantitative analysis, and data reduction methods of XRF spectrometry. (spectroscopyonline.com)
  • Fluorescence spectroscopy denotes a class of spectroscopy methods which are based on the analysis of fluorescence light, particularly concerning the emission spectrum. (rp-photonics.com)
  • However, there are also methods where one scans the excitation wavelength through a certain range and sometimes detects only the overall optical power of the fluorescence (without spectral analysis). (rp-photonics.com)
  • The concept Spectrometry, Fluorescence -- methods -- Congresses represents the subject, aboutness, idea or notion of resources found in University of Liverpool . (liverpool.ac.uk)
  • My research is continuously trying to improve the accuracy and precision of major and trace element analysis of various geological materials by wavelength dispersive X-ray fluorescence (WDXRF) spectrometry. (spectroscopyonline.com)
  • SMART-Control adds Application processing and interface protocols- WiFi, RS232, SPI, … In fluorescence spectroscopy both excitation and emission wavelengths are characteristic. (theredbeat.com)
  • Abstract: Time-resolved fluorescence measurements reveal intermolecular interactions depending upon the environment of the fluorophore. (horiba.com)
  • This paper describes the basic background and some examples of how the fluorescence lifetime is more informative than steady-state fluorescence measurements. (horiba.com)
  • 7. Four collection modes enable you to do more on one instrument: Fluorescence, Phosphorescence, Chemi/Bio-Luminescence, and Time Resolved Phosphorescence measurements. (monash.edu.my)
  • For steady-state fluorescence measurements it is usually measured by embedding the fluorophore in a frozen polyol. (wikipedia.org)
  • Cold vapour atomic fluorescence spectroscopy, sometimes referred to by the acronym CVAFS, is a subset of the analytical technique known as atomic fluorescence spectroscopy (AFS). (tps-dp.com.ua)
  • mercury â Cold vapour atomic fluorescence spectrometry (CVAFS) Qualité du sol â Dosage du mercure â Spectrométrie de fluorescence atomique à vapeur froide (CVAFS) TECHNICAL SPECIFICATION ISO/TS 16727 First edition 2013-09-15 Reference number ISO/TS 16727:2013(E) Corrected version A method for the determination of total mercury in rat adipose tissue by cold vapour atomic fluorescence spectrometry (CVAFS) has been developed. (tps-dp.com.ua)
  • While atomic absorption can also measure mercury concentrations, it is not as sensitive or selective as cold vapour atomic fluorescence spectroscopy (CVAFS). (theredbeat.com)
  • The liquid chromatography-cold vapour atomic fluorescence spectrometry (LC/CV-AFS) method was optimised and used for separation and determination of inorganic mercury cations and alkylated and arylated mercury species. (tps-dp.com.ua)
  • The mixture of surfactant Triton X-114 micelle and octanol was innovatively used as the non-aqueous media for the CVG and atomic fluorescence spectrometry (AFS) was used for the elemental determination. (progettovoce.com)
  • Non-dispersive atomic-fluorescence spectrometry for the determination of mercury and its application to fish samples. (theredbeat.com)
  • Study of the application of atomic fluorescence spectrometry to the direct determination of mercury and cadmium in the atmosphere. (theredbeat.com)
  • atomic fluorescence spectrometry was developed by the U.S. Geological Survey in 2001 for the determination of organic plus inorganic mercury in filtered and unfiltered natural water. (usgs.gov)
  • 1.1 This procedure covers the determination of aldicarb, carbofuran, oxamyl and methomyl (referred to collectively as carbamates in this test method) in surface water by direct injection using liquid chromatography (LC) and detected with tandem mass spectrometry (MS/MS). These analytes are qualitatively and quantitatively determined by this method. (environmental-expert.com)
  • Objective To develop a method for the determination of trace mercury in waste water by atomic fluorescence spectrometry . (bvsalud.org)
  • However, in the case of elements of low atomic number, such as silicon, direct determination is hampered due to low fluorescence yield and relatively low energy easily absorbed by sample matrix. (scribd.com)
  • Determination of Arsenic Speciation in Scomberomorus Niphonius by Capillary Electrophoresis-Inductively Coupled Plasma Mass Spectrometry [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2014, 34(06): 1675-1678. (gpxygpfx.com)
  • Standard linear filters are not effective for reducing noise in liquid chromatography-mass spectrometry (LC-MS) data because they assume a normal distribution of noise. (google.com)
  • The Ion Micro-Probe (Secondary Ion Mass Spectrometry, SIMS) Facility is located in the School of GeoSciences, Grant Institute at the University of Edinburgh. (ed.ac.uk)
  • The performance and accuracy of energy dispersive X-ray fluorescence (ED-XRF) spectrometry performing elemental analysis in the field on soil and sewage sludge samples are detailed in a new application brief - available to download at http://goo.gl/W6xEnY. (environmental-expert.com)
  • SPECTRO Analytical Instruments announces the introduction of its new SPECTROSCOUT Portable Energy Dispersive X-ray Fluorescence (ED-XRF) analyzer that enables rapid, laboratory-class elemental analysis of environmental and geological samples even in remote locations. (environmental-expert.com)
  • Among the modular tags produced we found several combinations that were optimal for determining subcellular localization and for purifying the tagged proteins and protein complexes for the detailed analysis by mass spectrometry. (mcponline.org)
  • The x-ray fluorescence analysis showed that the concentrations of elements, such as silicon, calcium, iron, and zinc, were higher in the oily wastewater than those in the unused cutting oil. (springer.com)
  • X-ray fluorescence (XRF) spectroscopy is one of the simplest and most widely used techniques for the non-destructive multielement analysis of materials. (spectroscopyeurope.com)
  • Micro X-ray fluorescence spectrometry (Micro-XRF) is the method of choice for the elemental analysis of non-homogeneous or irregularly shaped samples as well as small samples or even inclusions. (bruker.com)
  • Atomic fluorescence spectrometry: A review of advances in instrumentation and novel applications Atomic fluorescence spectrometry (AFS) is a commonly employed method for elemental analysis employed with chemical vapor generation procedures due to its low cost and high sensitivity. (theredbeat.com)
  • We provide specialised X-Ray Fluorescence (XRF) services including a range of sample preparation facilities and the analysis of a wide variety of sample types including soils, ores, mineral sands, and plant materials. (www.csiro.au)
  • The application of X-Ray Fluorescence (XRF) to elemental analysis at the CSIRO Land and Water Adelaide Laboratory goes back to the early days of XRF spectrometry. (www.csiro.au)
  • The authenticity of the histamine like fluorescence was checked by treating some of the samples with diamine-oxidase before fluorometric analysis. (cdc.gov)
  • Further synchrotron radiation analysis of a number of these entrapped particles shows them to exist as UO 2 -identical to reactor fuel, with confirmation of their nuclear origin shown via mass spectrometry analysis. (nature.com)
  • In addition, the specific chemical structure of the aflatoxin B 1 -lysine adduct in human samples was confirmed for the first time by collision-induced dissociation full scan mass spectrometry analysis of the protonated adduct molecular ion. (aacrjournals.org)
  • Finally, LA-ICP-MS-imaging ( 165 Ho) was linked to fluorescence-based analysis of excised tissue samples (Cy5). (nih.gov)
  • X radiation emitted by atoms excited by absorption of X-radiation.Fluorescence techniques are more complex to implement than is the case for absorption techniques, since they entail that the particle subjected to analysis be selectively excited by a monochromatic radiation. (ukessays.com)
  • The growing number of genetic tests has been made possible by advances in technology, including advances in chromosomal analysis - from traditional karyotyping to fluorescence in situ hybridization (FISH), and then to chromosomal microarrays and next generation sequencing. (prnewswire.com)
  • In combination with hydride generation-atomic fluorescent spectrometry (HG-AFS), speciation analysis of inorganic As(Ⅲ) and As(Ⅴ) in water samples could be accomplished because Fe(Ⅲ) modified Na had various micro-extraction behavior for inorganic As(Ⅲ) and As(Ⅴ) respectively. (gpxygpfx.com)
  • The Progress in Speciation Analysis of Trace Elements by Atomic Spectrometry [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2013, 33(12): 3377-3382. (gpxygpfx.com)
  • The Hamamatsu Picosecond fluorescence lifetime measurement system has been developed in response to the requirements from researchers studying such materials. (hamamatsu.com)
  • Picosecond fluorescence lifetime measurement system C11200 has been saved to your wishlist successfully. (hamamatsu.com)
  • After a short delay (the average represented as the fluorescence lifetime τ {\displaystyle \tau } ), it comes down to a lower state by losing some of the energy as heat and emitting the rest of the energy as another photon. (wikipedia.org)
  • Taking the idealistic simplest case a subset of dye molecules suspended in solution that have a mono-exponential fluorescence lifetime τ {\displaystyle \tau } and r0=0.4 (rhodamine 6g in ethylene glycol made to have an absorbance of ~0.05 is a good test sample). (wikipedia.org)
  • Bonding mechanism of human serum albumin(HSA) and dibutyltin(DBT) that is the degradation product of tributyltin(TBT)which is main component of antifouling paint of ships on molecular level was investigated by fluorescence spectrometry for finding out the way and degree of mutual combination. (cnki.com.cn)
  • Elemental mercury produced after adding stannous chloride is purged from the solution with ultrapure argon gas into a cell in which the mercury concentration is measured by atomic fluorescence emission at 253.7 nanometers. (usgs.gov)
  • The new device uses this fluorescence spectrum as a sort of a fingerprint to identify the oil type by comparing the measured fluorescence with information in a database. (azooptics.com)
  • Wikipedia article "Cold_vapour_atomic_fluorescence_spectroscopy", Cold_vapour_atomic_fluorescence_spectroscopy, US EPA Method 245.7 for Measurement of Mercury in Waters. (progettovoce.com)
  • Fluorescence Spectroscopy Yevgen Povrozin and Beniamino Barbieri Published in Handbook of Measurement in Science and Engineering, vol. (theredbeat.com)
  • PS Analytical's measurement systems are based on the PSA 10.525 Sir Galahad atomic fluorescence instrument. (petro-online.com)
  • Simultaneous measurement of fluorescence emission identifies the fluid type and ensures that samples are single phase, acquired above the gas condensate dewpoint. (slb.com)
  • One of the variants of TXRF, often referred as fluorescence-assisted X-ray standing wave (XSW) is a powerful and versatile tool to unfold depth-resolved physical and chemical properties of nanostructured materials, as it combines the features of both X-ray reflectivity (XRR) and XRF techniques. (spectroscopyeurope.com)
  • The major reasons for more usage of molecular fluorescence spectrometry in comparison to molecular phosphorescence spectrometry should be discussed. (bartleby.com)
  • EN] Molecular mechanics techniques and the use of atomic force fields have been used to calculate t. (universia.net)
  • In this study a bimodal (or rather, hybrid) tracer that contains both a fluorescent dye and a chelate was used to evaluate the existence of a direct link between mass spectrometry (MS) and in vitro and in vivo molecular imaging findings using fluorescence and radioisotopes. (nih.gov)
  • Spectrometry is the spectroscopic technique used to assess the concentration or amount of a given chemical (atomic, molecular, or ionic) species. (ukessays.com)
  • Conformational Modulation of the Farnesoid X Receptor by Prenylflavonoids: Insights from Hydrogen Deuterium Exchange Mass Spectrometry (HDX-MS), Fluorescence Titration and Molecular Docking Studies. (oregonstate.edu)
  • We combined Hydrogen Deuterium Exchange Mass Spectrometry (HDX-MS) with computational studies for dissecting molecular recognition and conformational impact of prenylflavonoid interactions on the ligand binding domain (LBD) of human FXR. (oregonstate.edu)
  • The AFB 1 -lys adduct has been shown to be present in rat albumin by full scan and tandem mass spectrometry, such confirmatory spectra have not been reported for human albumin samples collected in exposed populations ( 8 , 13 ). (aacrjournals.org)
  • Denton, MB & Malmstadt, HV 1972, ' Ultrasonic nebulization in a low-emission flame for atomic fluorescence spectrometry ', Analytical chemistry , vol. 44, no. 11, pp. 1813-1818. (elsevier.com)
  • This broad textbook in inorganic mass spectrometry, presents the most important mass spectrometric techniques used in all fields of analytical chemistry. (wiley.com)
  • Spectroscopy or spectrometry is often used in physical and analytical chemistry for the identification of substances through the spectrum emitted from or absorbed by them. (ukessays.com)
  • We propose a method which combines liquid chromatography (LC) in three orthogonal dimensions together with fluorescence polarization (FP) and mass spectrometry (MS) to identify target proteins in complex mixtures. (uio.no)
  • We identified endogenous S -nitrosylated proteins by mass spectrometry and/or immunoblotting with specific antibodies. (diabetesjournals.org)
  • The ability to accurately quantify proteins in formalin-fixed paraffin-embedded tissues using targeted mass spectrometry opens exciting perspectives for biomarker discovery. (mcponline.org)
  • Concept introduction: Phosphorescence spectrometry is closely related to fluorescence. (bartleby.com)
  • When the excitation is caused by selective absorption, by the atoms or molecules to be analyzed, of electromagnetic radiation,this represents a fluorescence emission (or a phosphorescence emission, depending on the electron excitation start involved). (ukessays.com)
  • Certain minerals have a characteristic fluorescence pattern when hit with white light or ultraviolet light. (encyclopedia.com)
  • Semen stains, for example, may be identified by their characteristic fluorescence under ultraviolet light examination. (encyclopedia.com)
  • When crude or refined oil absorbs ultraviolet (UV) light, it emits a unique fluorescence spectrum. (azooptics.com)
  • In this application note we decided to use spectroscopic ellipsometry, steady-state and time-resolved fluorescence and Glow Discharge Optical Emission Spectroscopy to investigate the properties of CH3NH3PbI3 thin films deposited on a spin-coated PEDOT:PSS. (theredbeat.com)
  • In other words, fluorescence is the luminescence that persists for less than about 10-8 s after excitation. (photonics.com)
  • High-intensity, spiked noise is reduced in chromatography-mass spectrometry data by applying a nonlinear filter such as a moving median filter to the data. (google.com)
  • Newly published ASTM D8064-16 standard test method has been approved for the quantification of heavy metal elements in soil and solid waste by monochromatic Energy-Dispersive X-ray Fluorescence (EDXRF) spectrometry using multiple monochromatic excitation beams - also known as High-Definition X-ray Fluorescence (HDXRF). (environmental-expert.com)
  • The quantities of internalized CPPs measured by fluorometry in cell lysates converge with those obtained by our previously reported mass spectrometry quantification method. (ens.fr)
  • It is capable of recording excitation, emission or synchronous fluorescence spectra. (stthomas.edu)
  • Total arsenic concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) after microwave digestion and ranged from 23 to 126 μg g−1. (universia.net)
  • Exploring fluorescence and fragmentation of ions produced by electrospray ionization in ultrahigh vacuum. (springer.com)
  • Principles, Methodologies, and Applications of Atomic Fluorescence Spectrometry. (theredbeat.com)
  • The principles of fluorescence polarization and some applications of the method are presented in Lakowicz's book. (wikipedia.org)
  • PerkinElmer, Inc have announced the launch of its FL 6500™ Pulse Xenon and FL 8500™ Continuous Wave Fluorescence Spectrometers. (labmate-online.com)
  • In conclusion, the developed assay showed good analytical performance and a high agreement with immunohistochemistry and fluorescence in situ hybridization data. (mcponline.org)
  • HORIBA has many fluorescence technologies and resources. (horiba.com)