Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Tandem 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.Spectrometry, Mass, Electrospray Ionization: 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.Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization: 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.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Chromatography, Liquid: Chromatographic techniques in which the mobile phase is a liquid.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Proteomics: The systematic study of the complete complement of proteins (PROTEOME) of organisms.Spectrometry, Mass, Secondary Ion: 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.Proteome: The protein complement of an organism coded for by its genome.Molecular Sequence Data: 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.Amino Acid Sequence: 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.Spectrometry, Mass, Fast Atom Bombardment: 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.Electrophoresis, Gel, Two-Dimensional: 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.Deuterium Exchange Measurement: A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.Peptides: 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.Isotope Labeling: 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.Molecular Structure: 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.Peptide Mapping: 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.Reproducibility of Results: 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.Reference Standards: 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.Calibration: 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.Magnetic Resonance Spectroscopy: 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).Solid Phase Extraction: 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: Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.Carbohydrate Sequence: The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.Sensitivity and Specificity: 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)Limit of Detection: Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.Proteins: 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.Ions: 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.Body Mass Index: An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)Metabolomics: 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.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Substance Abuse Detection: Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.Chromatography, Thin Layer: 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)Chromatography, Gas: 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.Fourier Analysis: 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)Cyclotrons: 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.Indicators and Reagents: 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)Protein Processing, Post-Translational: 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.Isotopes: Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)Analytic Sample Preparation Methods: 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.Protein Binding: 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.Trypsin: 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.Metabolome: The dynamic collection of metabolites which represent a cell's or organism's net metabolic response to current conditions.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.PolysaccharidesGlycosylation: 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.Oligosaccharides: 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.Carbohydrate Conformation: The characteristic 3-dimensional shape of a carbohydrate.Molecular Weight: The sum of the weight of all the atoms in a molecule.Sequence Analysis, Protein: A process that includes the determination of AMINO ACID SEQUENCE of a protein (or peptide, oligopeptide or peptide fragment) and the information analysis of the sequence.Isomerism: 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)Chromatography, Reverse-Phase: 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.Oxidation-Reduction: 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).Indicator Dilution Techniques: 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)Cattle: 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.Electrophoresis, Capillary: 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)Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Complex Mixtures: 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.Biotransformation: 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.Oxygen Isotopes: Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.Gases: 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)Recombinant Proteins: Proteins prepared by recombinant DNA technology.Chemical Fractionation: Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Biological Markers: 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.Spectrophotometry, Atomic: Spectrophotometric techniques by which the absorption or emmision spectra of radiation from atoms are produced and analyzed.Bacterial Proteins: Proteins found in any species of bacterium.Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Microchemistry: 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.Protein Array Analysis: Ligand-binding assays that measure protein-protein, protein-small molecule, or protein-nucleic acid interactions using a very large set of capturing molecules, i.e., those attached separately on a solid support, to measure the presence or interaction of target molecules in the sample.Forensic Medicine: The application of medical knowledge to questions of law.Hydrogen: 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.Atmospheric Pressure: The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Nanotechnology: The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Spectrophotometry, Ultraviolet: 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)Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Kinetics: The rate dynamics in chemical or physical systems.Spectroscopy, Fourier Transform Infrared: 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.Glycosphingolipids: Lipids containing at least one monosaccharide residue and either a sphingoid or a ceramide (CERAMIDES). They are subdivided into NEUTRAL GLYCOSPHINGOLIPIDS comprising monoglycosyl- and oligoglycosylsphingoids and monoglycosyl- and oligoglycosylceramides; and ACIDIC GLYCOSPHINGOLIPIDS which comprises sialosylglycosylsphingolipids (GANGLIOSIDES); SULFOGLYCOSPHINGOLIPIDS (formerly known as sulfatides), glycuronoglycosphingolipids, and phospho- and phosphonoglycosphingolipids. (From IUPAC's webpage)Chromatography, Affinity: A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Escherichia coli: 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.Protein Conformation: 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).Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Databases, Protein: Databases containing information about PROTEINS such as AMINO ACID SEQUENCE; PROTEIN CONFORMATION; and other properties.Methylation: Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Glycomics: The systematic study of the structure and function of the complete set of glycans (the glycome) produced in a single organism and identification of all the genes that encode glycoproteins.Chromatography, Ion Exchange: Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.Chemistry Techniques, Analytical: Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Carbon Isotopes: Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.Cross-Linking Reagents: Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Protein Structure, Tertiary: 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.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Stereoisomerism: 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)Blood Proteins: Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.Volatile Organic Compounds: Organic compounds that have a relatively high VAPOR PRESSURE at room temperature.PhosphopeptidesLysine: An essential amino acid. It is often added to animal feed.Acetonitriles: Compounds in which a methyl group is attached to the cyano moiety.Forensic Toxicology: The application of TOXICOLOGY knowledge to questions of law.Protein Interaction Mapping: Methods for determining interaction between PROTEINS.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Nitrogen Isotopes: Stable nitrogen atoms that have the same atomic number as the element nitrogen, but differ in atomic weight. N-15 is a stable nitrogen isotope.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Drug Stability: The chemical and physical integrity of a pharmaceutical product.Glucuronides: Glycosides of GLUCURONIC ACID formed by the reaction of URIDINE DIPHOSPHATE GLUCURONIC ACID with certain endogenous and exogenous substances. Their formation is important for the detoxification of drugs, steroid excretion and BILIRUBIN metabolism to a more water-soluble compound that can be eliminated in the URINE and BILE.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Hydrogen-Ion Concentration: 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)Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Glycopeptides: Proteins which contain carbohydrate groups attached covalently to the polypeptide chain. The protein moiety is the predominant group with the carbohydrate making up only a small percentage of the total weight.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Carbohydrates: The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.Solid Phase Microextraction: A solventless sample preparation method, invented in 1989, that uses a fused silica fiber which is coated with a stationary phase. It is used for sample cleanup before using other analytical methods.Brain Chemistry: Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.Mutation: 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.Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)EstersGlycerophospholipids: Derivatives of phosphatidic acid in which the hydrophobic regions are composed of two fatty acids and a polar alcohol is joined to the C-3 position of glycerol through a phosphodiester bond. They are named according to their polar head groups, such as phosphatidylcholine and phosphatidylethanolamine.Hair: A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.Neonatal Screening: The identification of selected parameters in newborn infants by various tests, examinations, or other procedures. Screening may be performed by clinical or laboratory measures. A screening test is designed to sort out healthy neonates (INFANT, NEWBORN) from those not well, but the screening test is not intended as a diagnostic device, rather instead as epidemiologic.Glycolipids: Any compound containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol (see GLYCERIDES), a sphingoid, a ceramide (CERAMIDES) (N-acylsphingoid) or a prenyl phosphate. (From IUPAC's webpage)Gentisates: Salts and esters of gentisic acid.Immunoassay: 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.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Immunoprecipitation: The aggregation of soluble ANTIGENS with ANTIBODIES, alone or with antibody binding factors such as ANTI-ANTIBODIES or STAPHYLOCOCCAL PROTEIN A, into complexes large enough to fall out of solution.Specimen Handling: Procedures for collecting, preserving, and transporting of specimens sufficiently stable to provide accurate and precise results suitable for clinical interpretation.Hydroxylation: Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)Sequence Analysis: A multistage process that includes the determination of a sequence (protein, carbohydrate, etc.), its fragmentation and analysis, and the interpretation of the resulting sequence information.Models, Biological: 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.Volatilization: A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.Solvents: 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)Computational Biology: A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.Microsomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.Cell Line, Tumor: A cell line derived from cultured tumor cells.Metabolism, Inborn Errors: Errors in metabolic processes resulting from inborn genetic mutations that are inherited or acquired in utero.Chromatography: Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Proteolysis: Cleavage of proteins into smaller peptides or amino acids either by PROTEASES or non-enzymatically (e.g., Hydrolysis). It does not include Protein Processing, Post-Translational.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Principal Component Analysis: Mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components.Trifluoroacetic Acid: A very strong halogenated derivative of acetic acid. It is used in acid catalyzed reactions, especially those where an ester is cleaved in peptide synthesis.Alkylation: The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.Plant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Lasers: 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.DNA Adducts: The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.Quality Control: A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)Horses: Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.Protein Isoforms: Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.Temperature: 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.Molecular Imaging: 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.Aldehydes: Organic compounds containing a carbonyl group in the form -CHO.Blood Chemical Analysis: An examination of chemicals in the blood.Disaccharides: Oligosaccharides containing two monosaccharide units linked by a glycosidic bond.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Doping in Sports: Illegitimate use of substances for a desired effect in competitive sports. It includes humans and animals.Multiprotein Complexes: Macromolecular complexes formed from the association of defined protein subunits.Molecular Conformation: The characteristic three-dimensional shape of a molecule.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Pharmaceutical Preparations: Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.Radioisotope Dilution Technique: Method for assessing flow through a system by injection of a known quantity of radionuclide into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Membrane Proteins: 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.Urinalysis: Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically.Electrons: Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.Glycosides: Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Liquid-Liquid Extraction: The removal of a soluble component from a liquid mixture by contact with a second liquid, immiscible with the carrier liquid, in which the component is preferentially soluble. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Monosaccharides: Simple sugars, carbohydrates which cannot be decomposed by hydrolysis. They are colorless crystalline substances with a sweet taste and have the same general formula CnH2nOn. (From Dorland, 28th ed)Spectrophotometry, Infrared: 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)Microbiological Techniques: Techniques used in microbiology.Solutions: 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)Metals: Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)Two-Dimensional Difference Gel Electrophoresis: Methods of comparing two or more samples on the same two-dimensional gel electrophoresis gel.Spectrum Analysis: 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)Methanol: A colorless, flammable liquid used in the manufacture of FORMALDEHYDE and ACETIC ACID, in chemical synthesis, antifreeze, and as a solvent. Ingestion of methanol is toxic and may cause blindness.Veterinary Drugs: Drugs used by veterinarians in the treatment of animal diseases. The veterinarian's pharmacological armamentarium is the counterpart of drugs treating human diseases, with dosage and administration adjusted to the size, weight, disease, and idiosyncrasies of the species. In the United States most drugs are subject to federal regulations with special reference to the safety of drugs and residues in edible animal products.Cells, Cultured: 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.Amides: Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)Protein Subunits: Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.Californium: Californium. A man-made radioactive actinide with atomic symbol Cf, atomic number 98, and atomic weight 251. Its valence can be +2 or +3. Californium has medical use as a radiation source for radiotherapy.Trimethylsilyl Compounds: Organic silicon derivatives used to characterize hydroxysteroids, nucleosides, and related compounds. Trimethylsilyl esters of amino acids are used in peptide synthesis.Phenols: Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.Swine: 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).Environmental Monitoring: The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.Sulfhydryl Compounds: Compounds containing the -SH radical.Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Acetylation: Formation of an acetyl derivative. (Stedman, 25th ed)Metabolic Networks and Pathways: Complex sets of enzymatic reactions connected to each other via their product and substrate metabolites.Tumor Markers, Biological: Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.Glucuronates: Derivatives of GLUCURONIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the 6-carboxy glucose structure.Coumaric Acids: Hydroxycinnamic acid and its derivatives. Act as activators of the indoleacetic acid oxidizing system, thereby producing a decrease in the endogenous level of bound indoleacetic acid in plants.Cluster Analysis: A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.DNA: 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).

Less common "doping" agents and substances encountered during routine screening for drugs. (1/17751)

The chromatographic and spectroscopic properties of several unusual substances which have been detected in the "alkaloidal" chloroform extract from racehorse urine and saliva samples are reported. Some of these substances have been identified by combined gas chromatography-mass spectrometry and the source of the substance is stated where this is known. Other substances whose identity is not known have been detected and their mass spectra show characteristic amine fragments. The occurrence of these unidentified substances is more frequent in aged urine samples and it would therefore appear that they are associated with putrefaction.  (+info)

Urinary lithium: distribution shape, reference values, and evaluation of exposure by inductively coupled plasma argon-emission spectrometry. (2/17751)

Inductively coupled plasma argon-emission spectrometry (ICPAES) was used to evaluate the lithium content of undiluted urine samples. The method can be performed with 1 mL of urine in a single tube using a routine ICPAES analysis for rapid and convenient assessment of lithium exposure in humans. Urine samples obtained from male workers (n = 86) who had not been exposed to lithium were used for the determination of this element by ICPAES. The obtained concentrations were corrected using a specific gravity of 1.024. The particular frequency distribution resulted in a log-normal distribution diagram for anatomical spread. Geometric mean value for urinary lithium in the nonexposed male workers was 23.5 microg/L, and the confidence interval from a log-normal distribution was 11.0 to 50.5 microg/L. Taking into consideration a short biological half-life and the massive urine excretion of lithium, urinary lithium was considered to be a useful index for monitoring of exposure. Calibration curves obtained for lithium standards had good sensitivity and linearity. Good reproducibility was assessed by lithium addition to urine samples. It was concluded that the obtained lithium reference values would be useful for the early diagnosis of lithium intoxication or in the assessment of the degree of exposure to lithium in subjects at risk.  (+info)

Archive of mass spectral data files on recordable CD-ROMs and creation and maintenance of a searchable computerized database. (3/17751)

A database containing names of mass spectral data files generated in a forensic toxicology laboratory and two Microsoft Visual Basic programs to maintain and search this database is described. The data files (approximately 0.5 KB/each) were collected from six mass spectrometers during routine casework. Data files were archived on 650 MB (74 min) recordable CD-ROMs. Each recordable CD-ROM was given a unique name, and its list of data file names was placed into the database. The present manuscript describes the use of search and maintenance programs for searching and routine upkeep of the database and creation of CD-ROMs for archiving of data files.  (+info)

UV irradiation of polycyclic aromatic hydrocarbons in ices: production of alcohols, quinones, and ethers. (4/17751)

Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultraviolet (UV) radiation under astrophysical conditions, and the products were analyzed by infrared spectroscopy and mass spectrometry. Peripheral carbon atoms were oxidized, producing aromatic alcohols, ketones, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account for the interstellar 3.4-micrometer emission feature. These classes of compounds are all present in carbonaceous meteorites. Hydrogen and deuterium atoms exchange readily between the PAHs and the ice, which may explain the deuterium enrichments found in certain meteoritic molecules. This work has important implications for extraterrestrial organics in biogenesis.  (+info)

Relationship between UDP-glucose 4-epimerase activity and oligoglucose glycoforms in two strains of Neisseria meningitidis. (5/17751)

Sodium dodecyl sulfate-polyacrylamide gel analysis of lipooligosaccharide (LOS) from Neisseria meningitidis has demonstrated considerable microheterogeneity in the variable region of LOS due to the presence of novel glycoforms. As a step toward understanding the basis for the expression of these novel glycoforms, we have examined the LOS structures and UDP-glucose 4-epimerase (epimerase) activity levels in two strains (NMB and MA-1) and their respective galE mutants. Strain NMB was found to have low epimerase activity and to contain multiple glycoforms, some of which appear to contain only glucose sugars. The galE mutant had only the oligoglucose glycoforms. Strain MA-1 had higher epimerase activity at both log and stationary phases (2- and 12.5-fold, respectively) and one glycoform with a putative lactosyl structure. Strain MA-1 galE had two glycoforms that contained one or two glucose residues. To understand the molecular basis for the different epimerase activities, we examined the predicted amino acid sequences of the respective galE open reading frames and determined the relative amounts of GalE protein. We found no significant differences between the predicted amino acid sequence of the GalE protein in NMB and that in MA-1. We observed no significant differences in the level of GalE protein between MA-1 and NMB at exponential or stationary phase. We also observed an 8.2-fold drop in epimerase activity in NMB between the log and stationary phases that was not due to the GalE protein level or low glucose levels.  (+info)

Insulin-like growth factors I and II are unable to form and maintain their native disulfides under in vivo redox conditions. (6/17751)

Insulin-like growth factor (IGF) I does not quantitatively form its three native disulfide bonds in the presence of 10 mM reduced and 1 mM oxidized glutathione in vitro [Hober, S. et al. (1992) Biochemistry 31, 1749-1756]. In this paper, we show (i) that both IGF-I and IGF-II are unable to form and maintain their native disulfide bonds at redox conditions that are similar to the situation in the secretory vesicles in vivo and (ii) that the presence of protein disulfide isomerase does not overcome this problem. The results indicate that the previously described thermodynamic disulfide exchange folding problem of IGF-I in vitro is also present in vivo. Speculatively, we suggest that the thermodynamic disulfide exchange properties of IGF-I and II are biologically significant for inactivation of the unbound growth factors by disulfide exchange reactions to generate variants destined for rapid clearance.  (+info)

Purification and identification of a novel subunit of protein serine/threonine phosphatase 4. (7/17751)

The catalytic subunit of protein serine/threonine phosphatase 4 (PP4C) has greater than 65% amino acid identity to the catalytic subunit of protein phosphatase 2A (PP2AC). Despite this high homology, PP4 does not appear to associate with known PP2A regulatory subunits. As a first step toward characterization of PP4 holoenzymes and identification of putative PP4 regulatory subunits, PP4 was purified from bovine testis soluble extracts. PP4 existed in two complexes of approximately 270-300 and 400-450 kDa as determined by gel filtration chromatography. The smaller PP4 complex was purified by sequential phenyl-Sepharose, Source 15Q, DEAE2, and Superdex 200 gel filtration chromatographies. The final product contained two major proteins: the PP4 catalytic subunit plus a protein that migrated as a doublet of 120-125 kDa on SDS-polyacrylamide gel electrophoresis. The associated protein, termed PP4R1, and PP4C also bound to microcystin-Sepharose. Mass spectrometry analysis of the purified complex revealed two major peaks, at 35 (PP4C) and 105 kDa (PP4R1). Amino acid sequence information of several peptides derived from the 105 kDa protein was utilized to isolate a human cDNA clone. Analysis of the predicted amino acid sequence revealed 13 nonidentical repeats similar to repeats found in the A subunit of PP2A (PP2AA). The PP4R1 cDNA clone engineered with an N-terminal Myc tag was expressed in COS M6 cells and PP4C co-immunoprecipitated with Myc-tagged PP4R1. These data indicate that one form of PP4 is similar to the core complex of PP2A in that it consists of a catalytic subunit and a "PP2AA-like" structural subunit.  (+info)

Identification of 17-methyl-18-norandrosta-5,13(17-dien-3beta-ol, the C19 fragment formed by adrenal side chain cleavage of a 20-aryl analog of (20S)-20-hydroxycholesterol. (8/17751)

Incubation of (20R)-20-phenyl-5-pregnene-3beta,20-diol, an aromatic analog of (23S)-20-hydroxycholesterol, with an adrenal mitochondrial preparation leads to the formation of four compounds: pregnenolone, phenol, a C8 ketone, acetophenone, and a nonpolar C19 compound. This latter compound has now been identified by reverse isotope dilution analysis and by gas chromatography/mass spectrometry as 17-methyl-18-norandrosta-5,13(17)-dien-3beta-ol. From these results it is evident that enzymatic fission of the C-17,20 bond of this synthetic derivative occurs. On the other hand, when (20S)-20-hydroxy[21-14C]cholesterol was used as substrate, the analogous cleavage did not take place. Thus, substitution of an aromatic group on C-20 facilitates side chain cleavage between that carbon atom and the nucleus whereas neither of the naturally occuring precursors, cholesterol or its 20-hydroxylated counterpart, are metabolized to a C8 fragment.  (+info)

  • Inductively Coupled Plasma-Mass Spectrometry (ICP) is a powerful technique of chemical characterization capable of simultaneously measuring up to 50 different trace elements, sometimes at concentrations as low as several parts per billion. (fieldmuseum.org)
  • Our Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Laboratory operates around a new Thermo ICAP Q quadrupole ICP-MS and a New Wave UP213 laser ablation system for solid sample introduction. (fieldmuseum.org)
  • Inductively Coupled Plasma Mass Spectrometry (ICP MS) provides analysis for a variety of elements, and with a sensitivity of a few ppb (ug/lit), depending on the analyte. (weizmann.ac.il)
  • The Teledyne CETAC Aridus3 Desolvating Nebulizer System is a specialized liquid sample introduction accessory for inductively coupled plasma mass spectrometry (ICPâ€'MS). The Aridus3 can enhance analyte sensitivity up to 10 times or more and can greatly reduce solvent-based interferences such as oxides and hydrides. (environmental-expert.com)
  • Inductively Coupled Plasma Mass Spectrometry (ICP-MS) features microscale(10-6(, trace(10-9(, and ultratrace(10-12( element analysis techniques. (environmental-expert.com)
  • Because samples are analyzed in solid form, laborious and error prone dissolution procedures inherent to such techniques as Inductively Coupled Plasma-Mass Spectrometry are avoided. (gc.ca)
  • the primary ion beam is emitted across the sample while secondary mass spectra are recorded. (wikipedia.org)
  • However, if the analyte being tested has a low mass value then it can produce a similar looking spectra to that of a MALDI spectra. (wikipedia.org)
  • Mass spectra of literally hundreds of compounds, among them complex carbohydrates, a variety of organometallics, synthetic polyamides as well as complex alkaloids and other natural products, have been obtained using one of the afore mentioned ionization methods. (umsl.edu)
  • These first nanoelectromechanical system-mass spectrometry spectra, obtained with modest mass sensitivity from only several hundred mass adsorption events, presage the future capabilities of this approach. (nature.com)
  • In the Open Mass Spectrometry Search Algorithm (OMSSA), specificity is calculated by a classic probability score using an explicit model for matching experimental spectra to sequences. (nih.gov)
  • With technologies like QuanTof (for a new dimension in high-resolution exact mass MS), StepWave (for confirmation of trace components), Triwave (for characterization of complex mixtures), and MS E (for exact-mass ion spectra from your samples), your possibilities are endless. (waters.com)
  • In this way, simple and directly interpretable mass spectra were obtained from immunoglobuline M (ca. 1 MDa) and from von Willebrand factor, a group of proteins that play an important role in coagulation of blood (signals at 0.5, 1, 1.5 and 2 MDa). (innovations-report.com)
  • Results are displayed as spectra of the signal intensity of detected ions as a function of the mass-to-charge ratio. (wikipedia.org)
  • Typical mass spectra are presented for each operating condition. (sae.org)
  • The Ambient Mass Spectrometry Imaging system can image sample surfaces under ambient native conditions, without sample preparation, and generate accurate localized mass spectra. (wur.nl)
  • After tissue sectioning and transfer onto a conductive and transparent sample plate, the MALDI matrix is deposited, and data are acquired by recording mass spectra according to a raster of points covering the surface to be analyzed. (mcponline.org)
  • Mass spectra recorded with their coordinates on the tissue are processed, and molecular images of the localization of molecules can be reconstructed. (mcponline.org)
  • We offer a range of the most commonly used Mass Spectrometry standards needed for standardizing your mass spectra. (alfa.com)
  • The fast atom bombardment (FAB) mass spectra of bouvardin (1) 6-O-methylbouvardin (2), deoxybouvardin (3) and a synthetic analog (4) have been examined. (nih.gov)
  • Fragmentation pathways are postulated which account for most of the major ions observed in the FAB mass spectra of these potentially useful antitumor agents. (nih.gov)
  • We applied TagGraph to a published human proteomic dataset of 25 million mass spectra and tripled confident spectrum identifications compared to its original analysis. (nature.com)
  • Interpretation of mass spectra. (wikipedia.org)
  • The report "Mass Spectrometry Market - by Technology (Tandem LC-MS/Quadrupole/ICP-MS/Gas Chromatography - MS/TOF-MS/MALDI-TOF/Fourier Transform-MS) & by Application (Pharmaceutical/Biotechnology/Environment/Food & Beverages) - Global Trends & Forecast to 2018" , this report studies the global mass spectrometry market over the forecast period of 2013 to 2018. (pitchengine.com)
  • Tandem Quadrupole ( Triple Quadrupole ) Mass Spectrometry Waters innovative tandem quadrupole MS technology is designed for quantitative UPLC®-MS/MS. Our philosophy centers on making high performance accessible, robust and reliable. (waters.com)
  • The process that contains these two steps is known as tandem MS. For determining the peptide arrangements, mass data of fragment can be utilized. (news-medical.net)
  • Increasingly, tandem mass spectrometry (MS/MS) is being used for newborn screening because this laboratory testing technology substantially increases the number of metabolic disorders that can be detected from dried blood-spot specimens. (cdc.gov)
  • The introduction of tandem mass spectrometry (MS/MS) in the 1990s for population-based newborn screening has enabled health-care providers to detect an increased number of metabolic disorders in a single process by using dried blood-spot specimens routinely collected from newborns ( 13 ). (cdc.gov)
  • Application of tandem mass spectrometry for species identification is illustrated. (sae.org)
  • A liquid chromatography-tandem mass spectrometry multiresidue method for quantification of specific metabolites of organophosphorous pesticides, synthetic pyrethroids, selected herbicides, and DEET in human urine. (thefreedictionary.com)
  • Resulting peptides are extracted from the gel matrix and analyzed using reversed phase nano-litter flow liquid chromatography followed by tandem mass spectrometry. (carolinashealthcare.org)
  • Tandem mass spectrometry (TMS) and T-cell-receptor excision circles (TRECs) can identify early-onset ADA deficiency at birth, on dried blood spot (DBS) taken within the routine newborn screening procedure. (aaaai.org)
  • Emerging technologies in the field of MSI are MALDI imaging and secondary ion mass spectrometry imaging ( SIMS imaging ). (wikipedia.org)
  • Secondary ion mass spectrometry (SIMS) is used to analyze solid surfaces and thin films by sputtering the surface with a focused primary ion beam and collecting and analyzing ejected secondary ions. (wikipedia.org)
  • The ability of mass spectrometry to identify and, increasingly, to precisely quantify thousands of proteins from complex samples can be expected to impact broadly on biology and medicine. (nih.gov)
  • These high-resolution electrospray ionisation mass spectrometry instruments support a range of research projects focused on the study of proteins and complexes of protein with fragments, compounds and natural product extracts, known as bioaffinity mass spectrometry. (edu.au)
  • Mass-spectrometry based Reference Methods, well established for small molecules as glucose, cholesterol or steroid hormones, have not been available, until recently, for quantification of proteins. (ptb.de)
  • One present study is about mass spectrometric quantification of viral proteins. (ptb.de)
  • It is spectrometry based on the mass or weight of the proteins. (myeloma.org)
  • Based on the weight of monoclonal proteins, e.g. lambda or kappa, their mass can be distinguished in a very specific way - in a number of daltons, which is the expression of the weight. (myeloma.org)
  • The Mass Spectrometry Shared Resource provides services to elucidate the primary structure of novel proteins and to analyze protein/protein interactions, post-translational modifications and protein levels. (cshl.edu)
  • Like liquid chromatography-mass spectrometry , it allows analysis and detection even of tiny amounts of a substance. (wikipedia.org)
  • Therefore, when an identifying mass spectrum appears at a characteristic retention time in a GC-MS analysis, it typically increases certainty that the analyte of interest is in the sample. (wikipedia.org)
  • The Mass Spectrometry Data Center measures, compiles, evaluates, and correlates Standard Reference Data and develops and disseminates associated electronic databases and analysis software for industrially and environmentally important (bio)molecules. (nist.gov)
  • The services are provided with full "beginning-to-end" support that includes project evaluation and design, biochemical purifications, mass spectrometry sequencing, and data analysis performed within the core and by the experienced core personnel. (bcm.edu)
  • The trend towards biological analysis at increasingly smaller scales, ultimately down to the volume of an individual cell, continues, and mass spectrometry with a sensitivity of a few to single molecules will be necessary. (nature.com)
  • Domon, B. & Aebersold, R. Mass spectrometry and protein analysis. (nature.com)
  • The Mass Spectrometry Unit performs quantitative and qualitative analysis of organic molecules using Mass spectrometry. (sun.ac.za)
  • Services include GC-MS analysis, LC-MS analysis, accurate mass determinations and Proteomic analysis. (sun.ac.za)
  • During the past ten years a variety of methods involving mass spectrom- etry have been developed for the analysis of environmentally important compounds. (springer.com)
  • The Genedata session at the Biotherapeutics Analytical Summit will demonstrate how leading pharmaceutical companies have successfully automated the analysis of mass spectrometry data for site-specific glycosylation of biopharmaceuticals. (prweb.com)
  • Genedata Expressionist for Mass Spectrometry Poster Session: Bioanalytical Mass Spectrometry application for sequence identification, quantifying PTMs, intact protein, and host cell protein impurity analysis. (prweb.com)
  • ACD/Labs' mass spectrometry software offers a range of options, from routine to advanced packages, for ensuring efficient and effective MS data handling and analysis for small molecules. (acdlabs.com)
  • Means of delivering nonvolatile analytes into the gas phase for mass analysis. (edu.au)
  • Ambient ionization mass spectrometric analysis of human surgical specimens to distinguish renal cell carcinoma from healthy renal tissue. (urotoday.com)
  • Planar Chromatography-Mass Spectrometry focuses on a relatively new approach to chemical analysis in general, and to separation science in particular. (routledge.com)
  • Use this standard, a highly validated mammalian protein digest, as a quality control sample for mass spectrometry (MS) analysis of complex proteomic samples. (fishersci.com)
  • Calibrate and maintain quality control for liquid chromatography (LC) and mass spectrometry (MS) analysis of proteomic samples using the carefully validated Thermo Scientific™ Pierce™ BSA Protein Digest Standard, LC-MS Grade. (fishersci.com)
  • Separation of complex mixtures using hyphenated techniques e.g. ion mobility mass spectrometry, gas chromatography, ultra-high pressure liquid chromatography, direct analysis in real-time ionisation. (gre.ac.uk)
  • Each chapter provides guidance in using the appropriate methods for isolating and purifying the compound class prior to mass spectrometric analysis. (wiley.com)
  • The methods further involve integrating data obtained from mass spectrometry analysis of a plurality of series of hydrolyzed polymer fragments, and optionally provide statistical interpretation paradigms and computer software therefor. (google.com)
  • 19. The method of claim 1 wherein step (c) is accomplished using mass analysis modes selected from the group consisting of: time-of-flight, quadrapole, ion trap, and sector. (google.com)
  • A method apparatus wherein a plurality of electric fields and of orthogonal spray configurations of vaporized analyte are so combined as to enhance the efficiency of analyte detection and mass analysis. (google.com)
  • Ambient mass spectrometry imaging is a very new development and has already a wide range of application, especially in qualitative surface analysis. (wur.nl)
  • Macroscopic and microscopic spatially-resolved analysis of food contaminants and constituents using laser-ablation electrospray ionization mass spectrometry imaging. (wur.nl)
  • g , specific MALDI imaging analysis using the Tag-mass concept with anti-C-terminal REG-α and an anti-human IgG tag (reporter m/z 1309) and anti-orosomucoid and anti-human monoclonal antibody (reporter m/z 1569). (mcponline.org)
  • Thermo Scientific Linear ion trap-orbitrap (XL): protein ID, PTM analysis and intact mass measurement. (cshl.edu)
  • There is disclosed an apparatus for providing an ionized analyte for mass analysis by photon desorption comprising at least one layer (11) for contacting an analyte, and a substrate (10) on which said layer (11) is deposited. (google.ca)
  • Upon irradiation of said app aratus, said analyte desorbs and ionizes for analysis by mass spectrometry. (google.ca)
  • a substrate on which said layer is deposited, wherein said analyte upon irradiation of said apparatus with a photon source desorbs and ionizes for mass analysis. (google.ca)
  • Real Time Sampling and Analysis of Biological Biomarkers by TOF Mass Spectrometry," SAE Technical Paper 981740, 1998, https://doi.org/10.4271/981740 . (sae.org)
  • NRC's Glow Discharge Mass Spectrometry (GDMS) service provides Canadian and international clients with accurate and timely, inorganic mass spectrometric analysis at a level of quality and service expected of a world class ISO/IEC 17025 accredited National Metrology Laboratory. (gc.ca)
  • Glow Discharge Mass Spectrometry (GDMS) enables the elemental analysis of solid samples by sputtering in a low-pressure DC argon discharge. (gc.ca)
  • Matrix-assisted laser desorption ionization can be used as a mass spectrometry imaging technique for relatively large molecules. (wikipedia.org)
  • With our three staff operated instruments, we provide services for molecular formula confirmation (accurate mass measurement), structural elucidation (MS/MS) and quantitation of small molecules. (google.com)
  • With origins in basic research, mass spectrometry emerged as a clinical research tool when it was first applied to fingerprint molecules for drug screening in the fight against drugs of abuse. (thefreedictionary.com)
  • 3. The apparatus of claim 2 wherein the analytical apparatus is capable of detecting and measuring the mass and charge of ionized molecules which have been communicated from the second passageway exit into the analytical apparatus. (google.com)
  • Although they have several advantages, matrix-free methods are limited to low-molecular-weight molecules with a mass-to-charge ratio of less than 3000. (photonics.com)
  • Mass Spectrometry Imaging Bringing together the powerful technologies of MALDI and DESI to discover, identify, and measure a broad range of molecular targets, delivering multi-layered, information-rich data from a single sample. (waters.com)
  • Ten years' evolution from one of the first MALDI images presented in 1999 at the 47th ASMS Conference on Mass Spectrometry and Allied Topics ( left ) (reprinted with permission of Caprioli and co-workers (84)) and molecular images obtained by our group for mouse stem cells injected in brain tissue sections ( right ) (M. Wisztorski, C. Meriaux, M. Salzet, and I. Fournier, unpublished results). (mcponline.org)
  • Using a MASS-FIX workflow lab, it will be possible to use an automated MALDI machine (rather than immunofixation). (myeloma.org)
  • Mass spectrometry provides rapid and quantitative identification of protein species with relatively low sample consumption. (nature.com)
  • Time-of-flight Mass Spectrometry Waters Time-of-flight MS systems, featuring QuanTof and MS E technologies, provide the highest UPLC-MS performance to meet the needs of challenging qualitative and quantitative applications. (waters.com)
  • Mass Spectrometry for Quantitation Quantitative mass spectrometry in an analytical process that answers the important question of 'How much is in my sample? (waters.com)
  • The workshop brought together researchers, practitioners and laboratory managers from industry, academia, and government to present new results, discuss recent trends, and identify important problems in the area of quantitative mass spectrometry of synthetic polymers. (thefreedictionary.com)
  • Quantitative synthetic polymer mass spectrometry workshop. (thefreedictionary.com)
  • 24 October 2011 - UK pharmaceutical company Almac Group Ltd announced it had established a mass spectrometry laboratory at its headquarters in Northern Ireland worth GBP1m (USD1. (thefreedictionary.com)
  • Techniques to detect such compounds already exist, but these methods, such as mass spectrometry, are mostly confined to the laboratory because they are too bulky and complex to provide real-time, portable detection. (theengineer.co.uk)
  • As an initiative of the ASMS Diversity Committee, JASMS editors are pleased to share the "Faces of Mass Spectrometry" interview series. (asms.org)
  • We welcome nominations (and self-nominations) of members to profile in the Faces of Mass Spectrometry. (asms.org)
  • As part of the nomination we request a 300 word (max) statement to tell us 'Why this person be highlighted in the Faces of Mass Spectrometry and/or How does this person represent diversity in the ASMS? (asms.org)
  • As an initiative of the recently formed ASMS Diversity and Outreach Working Group, the editors are pleased to introduce a new "Faces of Mass Spectrometry" interview series in the Journal of the American Society of Mass Spectrometry. (asms.org)
  • The technological advancements and breakthroughs in the field of mass spectrometry such as increased speed, higher accuracy, improved resolution, and miniaturization are expected to drive the global market in the coming years. (pitchengine.com)
  • High-Mass option facilities, easier characterisation of high-molecular weight species and native state protein complexes. (edu.au)
  • GRIDD provides high-resolution mass measurement to determine the molecular formula of chemical entities as a service for Griffith researchers and external organisations. (edu.au)
  • Nanoelectromechanical systems provide unparalleled mass sensitivity, which is now sufficient for the detection of individual molecular species in real time. (nature.com)
  • Due to its structurally significant mass spectral peaks, extended range of analyzable low volatility samples, enhanced molecular ions, and valuable isotope ratio information, GC-MS is a powerful tool for geochemical applications. (news-medical.net)
  • Identify unknown components by screening their accurate mass and/or predicted molecular formula against the local PubChem database. (acdlabs.com)
  • In this issue of Clinical Chemistry, Muddiman and coworkers from the Mayo Clinic present reports in which two levels of mass spectrometry experiments are used to detect and characterize transthyretin variants by accurately measuring the molecular mass of the intact protein isolated from human serum (1, 2). (thefreedictionary.com)
  • It covers electrophoretic-mass spectrometry methods and applications, which are considered planar chromatographic techniques and are increasingly being exploited in proteomic and molecular biology studies as well as for medical diagnostic purposes. (routledge.com)
  • We used ESI-MS =-=(17)-=- to measure the potential zinc ion binding of SAG by comparing the molecular mass of SAG under denaturing and nondenaturing solution conditions (37, 72). (psu.edu)
  • Mass species representing molecular features of preinvasive and invasive lesions of the breast. (mcponline.org)
  • For masses above ~90 u, the mass resolution required to remove common molecular interferences exceeds the capability of SIMS for measuring trace species. (navy.mil)
  • A method comprising using a first mass analyzer of a downhole tool to isolate specific ions within a sample received in the downhole tool, using a second mass analyzer of the downhole tool to stabilize the ions isolated by the first mass analyzer, and using a third mass analyzer of the downhole tool to catalog the stabilized ions. (freepatentsonline.com)
  • and using a third mass analyzer of the downhole tool to catalog the stabilized ions. (freepatentsonline.com)
  • In fact, early spectrometry devices that measured the mass-to-charge ratio of ions were called mass spectrographs because they were instruments that recorded a spectrum of mass values on a photographic plate. (newworldencyclopedia.org)
  • A mass spectroscope is similar to a mass spectrograph except that the beam of ions is directed onto a phosphor screen. (newworldencyclopedia.org)
  • Sodium atoms and ions are monoisotopic , with a mass of about 23 amu. (newworldencyclopedia.org)
  • Has a mass range for singly charged ions of 10-2000 Daltons with unit resolution across the entire mass range. (edu.au)
  • One possibility would be to produce multiply charged ions and detect them in a more accessible mass-to-charge ratio range. (innovations-report.com)
  • Mass spectrometry ( MS ) is an analytical technique that measures the mass-to-charge ratio of ions . (wikipedia.org)
  • These ions are then separated according to their mass-to-charge ratio, for example by accelerating them and subjecting them to an electric or magnetic field: ions of the same mass-to-charge ratio will undergo the same amount of deflection. (wikipedia.org)
  • Time-of-flight mass spectrometry (TOF-MS) is a method of mass spectrometry in which ions mass-to-charge ratio is determined via a time measurement. (gre.ac.uk)
  • Rapid (ms) separation of ions based on shape, mass and charge. (gre.ac.uk)
  • The invention relates to a method and apparatus for obtaining improved signal relative to noise without loss of ion collection efficiency for use in mass spectrometry, including LC/MS (liquid chromatography/mass spectrometry), especially as regards the technique of generating analyte ions known as Atmospheric Pressure Chemical Ionization (APCI). (google.com)
  • Once deflected, the particles are detected and recorded electrically to provide a mass spectrum of the input beam of ions. (photonics.com)
  • Mass spectrometry (MS) is an analytical technique that ionizes chemical species and sorts the ions based on their mass-to-charge ratio. (wikipedia.org)
  • An extraction system removes ions from the sample, which are then targeted through the mass analyzer and onto the detector. (wikipedia.org)
  • The differences in masses of the fragments allows the mass analyzer to sort the ions by their mass-to-charge ratio. (wikipedia.org)
  • The principles behind mass spectrometry are somewhat abstract, so let's start with a concrete mental exercise. (howstuffworks.com)
  • Contributors from pharmaceuticals, biochemistry, and other biomedical disciplines review and illustrate the principles and applications of using mass spectrometry to study biomolecular interactions. (thefreedictionary.com)
  • Mass spectrometry imaging (MSI) integrates MS data with information on the spatial distributions of the analytes, further enhancing the applicability of MS. In Mass Spectrometry Imaging: Principles and Protocols, expert practitioners from academia, industry, and the clinic contribute cutting-edge protocols describing the application of MSI to investigations of analyte localization in a variety of specimens, from microorganisms to plant and animal tissues. (springer.com)
  • Comprehensive and up-to-date, Mass Spectrometry Imaging: Principles and Protocols is written for scientists, biological and chemical engineers, and clinicians who are interested in applying MSI in their work and those who would benefit from having detailed experimental guidelines available in a single, convenient source. (springer.com)
  • Mass spectrometry: principles and applications. (wikipedia.org)
  • These capabilities include advanced sample preparation combined with both LC-MS and GC-MS. High resolution accurate mass (HRAM) hyphenated with both GC and LC separation, enhanced-resolution triple quadrupole hyphenated with GC instrument and triple quadrupole LC systems for routine quantitation. (intertek.com)
  • Obtain both positive and negative ionization calibration of Thermo Scientific™ Triple Stage Quadrupole instruments using the Thermo Scientific™ Pierce™ Triple Quadrupole Calibration Solution, Extended Mass Range, which is a mixture of 14 highly pure, ionizable components (mass range: 69 m/z to 2800m/z). (fishersci.com)
  • The Quantum is a triple quadrupole instrument with high sensitivity and a broad mass range. (carolinashealthcare.org)
  • Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. (wikipedia.org)
  • This book overviews the combination of planar chromatography, a relatively simple and cost-effective separation step for determining complex mixtures of compounds, with mass spectrometry, an efficient, highly instrumental, and relatively expensive technique that enables rapid identification of separated chemical species. (routledge.com)
  • In our nanoelectromechanical-mass spectrometry system, nanoparticles and protein species are introduced by electrospray injection from the fluid phase in ambient conditions into vacuum, and are subsequently delivered to the nanoelectromechanical system detector by hexapole ion optics. (nature.com)
  • Mass spectrometry (MS) is considered to be a powerful method for quickly and efficiently identifying protein samples. (news-medical.net)
  • Then the program has to compare the measurements that are calculated from the digested protein represented in a database with an obtained peptide mass. (news-medical.net)
  • Therefore, PTB has developed Isotope Dilution Mass Spectrometry (ID-MS) for protein markers, expanding the scope of SI-traceable Reference Measurement to this important class of clinical measurands. (ptb.de)
  • Mass spectrometric protein quantification is used to explore measurands for research purposes in general. (ptb.de)
  • Intact protein mass measurement for drug binding and to support crystallographic studies. (cshl.edu)
  • Although mass spectrometry is well suited to identifying thousands of potential protein post-translational modifications (PTMs), it has historically been biased towards just a few. (nature.com)
  • Creasy, D. M. & Cottrell, J. S. Unimod: protein modifications for mass spectrometry. (nature.com)
  • Desalt, clean up and prep 25 to 150 microliter peptide samples for mass spectrometry with these ready-to-use microcentrifuge columns of C18 reverse-phase resin. (fishersci.com)
  • Covered in-depth are the mass spectrometry of carbohydrates, peptide sequencing by mass spectrometry, mass spectrometry of nucleic acid components, and mass spectrometry in pharmacology. (wiley.com)
  • Peptide Sequencing by Mass Spectrometry (J. Stults). (wiley.com)
  • Accelerator mass spectrometry (AMS) is a powerful method for the measurement of very low abundance nuclei (10 -9 to 10 -16 ) even in a background of much stronger isobars. (anl.gov)
  • Etalo D, de Vos RCH, Joosten MHAJ, Hall RD. Spatially-resolved plant metabolomics: some potentials and limitations of Laser-Ablation Electrospray Ionization (LAESI) Mass Spectrometry metabolite imaging. (wur.nl)
  • Touch spray-mass spectrometry (TS-MS) is an ambient ionization technique (ionization of unprocessed samples in the open air) that may find intraoperative applications in quickly identifying the disease state of cancerous tissues and in defining surgical margins. (urotoday.com)
  • As an undergraduate student researcher in the Bush Lab, Evan investigated fundamental aspects of electrospray ionization in the context of native mass spectrometry. (washington.edu)
  • The author wrote that atmospheric pressure ionization and matrix-free methods are easier to use than many ionization techniques, and that they might entice more casual users to employ mass spectrometry. (photonics.com)
  • Biological tissues and aqueous samples are readily analyzed using a mid-infrared laser (2940 nm) in Laser Ablation Electrospray Ionization Mass Spectrometry (or LAESI-MS). The wavelength corresponds to the frequency of the O-H bond vibrations in water, therefore it results in the strong absorption of this wavelength by the water. (wur.nl)
  • Ionization methods in organic mass spectrometry. (wikipedia.org)
  • Here, we report the first demonstration of mass spectrometry based on single biological molecule detection with a nanoelectromechanical system. (nature.com)
  • Single Quadrupole Mass Detection Waters innovative single quadrupole mass detectors are designed for robustness, to make access to mass spectral data easy for scientists with all levels of expertise. (waters.com)
  • This benchtop LC-MS/MS system combines quadruple precursor ion selection with high-resolution, accurate-mass (HRAM) Orbitrap detection to deliver exceptional performance and versatility. (environmental-expert.com)
  • Mass spectrometry, with its inherently high selectivity, has the promise to furnish much better resolution and is being investigated as a tool for detection and evaluation of isoforms. (ptb.de)
  • This permits compounds to be assigned to the Δ 4 or Δ 5 series on the basis of mass-spectrometric data. (springer.com)
  • The Mass Spectrometry Unit, part of the Central Analytical Facilities of Stellenbosch University, serves as a resource offering contemporary mass spectrometric techniques and the 'state-of-the-art' instrumen-tation needed for the diversity of research interests on- and off-campus. (sun.ac.za)
  • Below is a brief overview of the major mass spectrometric applications we currently support. (gre.ac.uk)
  • This unusual text is not simply a compilation of mass spectrometric methods but provides, instead, insight into specific approaches mass spectroscopists use when applying the technique to a variety of biological problems. (wiley.com)
  • Staff within the MSRL provide assistance with project design, sample preparation, collection and interpretation of mass spectrometric data. (rochester.edu)
  • In Mass Spectrometry of Glycoproteins: Methods and Protocols, expert researchers in the field detail many of the methods that are now commonly used for glycoproteomics. (springer.com)
  • Authoritative and practical, Mass Spectrometry of Glycoproteins: Methods and Protocol is an essential resource for those who work at the interface of glycobiology and mass spectrometry. (springer.com)
  • Aiming to improve power and efficiency when other analytical methods are inadequate, Planar Chromatography-Mass Spectrometry encourages separation science practitioners in academia and industry to combine the two methods for enhanced results. (routledge.com)
  • The methods and apparatus disclosed herein are useful for sequencing polymers using mass spectrometry. (google.com)
  • T he BUSM Mass Spectrometry Resource was funded by NIGMS as a Biotechnology Research Resource Center that was engaged in the development and application of mass spectral methods for biology and medicine with primary emphasis on studies of oligosaccharides and glycoconjugates. (bu.edu)
  • Mass spectroscopes also are employed to separate isotopes and to measure the abundance of concentrated isotopes when used as tracers in chemistry , biology, and medicine . (britannica.com)
  • This article will walk you through the unassuming but handy field of chemistry known as mass spectrometry . (howstuffworks.com)
  • Practical MS Education Package This package contains all the materials and equipment needed to introduce a practical course in MS fundamentals in which your organic chemistry students will have the opportunity to generate and interpret mass data themselves. (waters.com)
  • The journal invites papers in all fundamental aspects of mass spectrometry and ion processes , including instrumental developments and applications in biology , chemistry , geology and physics . (elsevier.com)
  • The Thermo Scientific Exactive GC (HRAM with 60,000 resolution and sub ppm mass accuracy, CI capability without vacuum venting) with SPME, static headspace (SHS) and multiple liquid injection capabilities supports component identification, elemental composition confirmation and MS quantitation. (intertek.com)
  • Wilhelm Wien found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with parallel electric and magnetic fields that separated the positive rays according to their charge-to-mass ratio (Q/m) . (newworldencyclopedia.org)
  • Wien found that the charge-to-mass ratio depended on the nature of the gas in the discharge tube. (newworldencyclopedia.org)
  • The multiply charged species are detected by their mass-to-charge ratio. (edu.au)
  • The results are typically presented as a mass spectrum , a plot of intensity as a function of the mass-to-charge ratio. (wikipedia.org)
  • A mass spectrum is a plot of the ion signal as a function of the mass-to-charge ratio. (wikipedia.org)
  • This series of rapid acquisitions has positioned GV Instruments to be a major player in inorganic mass spectrometry , especially isotope ratio mass spectrometry (ISMS). (thefreedictionary.com)
  • The IUPAC definition for resolution in mass spectrometry is R = M Δ M {\displaystyle R={\cfrac {M}{\Delta M}}} = resolution Δ M {\displaystyle \Delta M} = resolving power M {\displaystyle M} = mass of the (second) peak Where a larger resolution indicates a better separation of peaks. (wikipedia.org)
  • There are several ways to define the minimum peak separation ΔM in mass spectrometry, therefore it is important to report the method used to determine mass resolution when reporting its value. (wikipedia.org)
  • Precipitous frequency shifts, proportional to the mass, are recorded in real time as analytes adsorb, one by one, onto a phase-locked, ultrahigh-frequency nanoelectromechanical resonator. (nature.com)
  • The mass spectrometry process normally requires a very pure sample while gas chromatography using a traditional detector (e.g. (wikipedia.org)
  • The improved ultrafast, 2-μm-pore MCP TOF detector offered by Burle Electro-Optics Inc. is suitable for mass spectrometry applications. (photonics.com)
  • Using this technique has resulted in an increase of sensitivity for larger mass samples. (wikipedia.org)
  • This system (installed end 2015) combines a state-of-the-art segmented quadrupole for high-performance precursor ion selection with a high-resolution, accurate-mass (HR/AM) ultra-high-field Orbitrap mass analyzer to deliver a superior combination of scan speed, resolving power, mass accuracy, spectral quality and sensitivity. (edu.au)
  • Accurate mass measurements to determine elemental composition, high sensitivity MS and MS/MS measurements. (gre.ac.uk)
  • Figures of merit such as resolving power, mass accuracy, dynamic range and sensitivity of each type of instrument are compared. (psu.edu)
  • The Warwick Mass Spectrometry community includes scientists with a wide range of technical and applications expertise. (warwick.ac.uk)
  • An animated conversation with Diversity and Outreach Working Group member Dr. Livia Eberlin introduced science writer Kristin Phillips to the astounding capability of mass spectrometry and sparked this series of conversations with innovative, creative scientists of ASMS. (asms.org)
  • T he mission of the Boston University Mass Spectrometry Resource for Biology and Medicine was to pursue sophisticated mass spectrometry in an environment with close interaction with life scientists and physicians. (bu.edu)