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.Specimen Handling: Procedures for collecting, preserving, and transporting of specimens sufficiently stable to provide accurate and precise results suitable for clinical interpretation.Chemistry Techniques, Analytical: Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.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.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)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.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.United StatesFood, Preserved: Food that has been prepared and stored in a way to prevent spoilage.Cooking: The art or practice of preparing food. It includes the preparation of special foods for diets in various diseases.Bisacodyl: A diphenylmethane stimulant laxative used for the treatment of CONSTIPATION and for bowel evacuation. (From Martindale, The Extra Pharmacopoeia, 30th ed, p871)Histocytological Preparation Techniques: Methods of preparing cells or tissues for examination and study of their origin, structure, function, or pathology. The methods include preservation, fixation, sectioning, staining, replica, or other technique to allow for viewing using a microscope.Longitudinal Studies: Studies in which variables relating to an individual or group of individuals are assessed over a period of time.Drug Compounding: The preparation, mixing, and assembling of a drug. (From Remington, The Science and Practice of Pharmacy, 19th ed, p1814)Cohort Studies: Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.Microwaves: That portion of the electromagnetic spectrum from the UHF (ultrahigh frequency) radio waves and extending into the INFRARED RAYS frequencies.Particle Size: Relating to the size of solids.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.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.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Molecular Medicine: The field of medicine concerned with understanding the biochemical basis of health and disease and involved in developing diagnostic and therapeutic methods that utilize MOLECULAR BIOLOGY techniques.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.Metabolome: The dynamic collection of metabolites which represent a cell's or organism's net metabolic response to current conditions.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).Gynostemma: A plant genus of the family CUCURBITACEAE. It is a source of gypenosides and triterpenoid SAPONINS.Molecular Biology: A discipline concerned with studying biological phenomena in terms of the chemical and physical interactions of molecules.Principal Component Analysis: Mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components.Microfluidic Analytical Techniques: Methods utilizing the principles of MICROFLUIDICS for sample handling, reagent mixing, and separation and detection of specific components in fluids.Microfluidics: The study of fluid channels and chambers of tiny dimensions of tens to hundreds of micrometers and volumes of nanoliters or picoliters. This is of interest in biological MICROCIRCULATION and used in MICROCHEMISTRY and INVESTIGATIVE TECHNIQUES.Dimethylpolysiloxanes: Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Lab-On-A-Chip Devices: Microdevices that combine microfluidics technology with electrical and/or mechanical functions for analyzing very small fluid volumes. They consist of microchannels etched into substrates made of silicon, glass, or polymer using processes similar to photolithography. The test fluids in the channels can then interact with different elements such as electrodes, photodetectors, chemical sensors, pumps, and valves.Equipment Design: Methods of creating machines and devices.Microchip Analytical Procedures: The preparation and analysis of samples on miniaturized devices.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.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Chromatography, Liquid: Chromatographic techniques in which the mobile phase is a liquid.Chloroform: A commonly used laboratory solvent. It was previously used as an anesthetic, but was banned from use in the U.S. due to its suspected carcinogenicity.Chondro-4-Sulfatase: An enzyme from the sulfuric ester hydrolase class that breaks down one of the products of the chondroitin lyase II reaction. EC Enzymes that catalyze the hydrolysis of a phenol sulfate to yield a phenol and sulfate. Arylsulfatase A, B, and C have been separated. A deficiency of arylsulfatases is one of the causes of metachromatic leukodystrophy (LEUKODYSTROPHY, METACHROMATIC). EC An arylsulfatase that catalyzes the hydrolysis of the 4-sulfate groups of the N-acetyl-D-galactosamine 4-sulfate units of chondroitin sulfate and dermatan sulfate. A deficiency of this enzyme is responsible for the inherited lysosomal disease, Maroteaux-Lamy syndrome (MUCOPOLYSACCHARIDOSIS VI). EC An enzyme that catalyzes the hydrolysis of cerebroside 3-sulfate (sulfatide) to yield a cerebroside and inorganic sulfate. A marked deficiency of arylsulfatase A, which is considered the heat-labile component of cerebroside sulfatase, has been demonstrated in all forms of metachromatic leukodystrophy (LEUKODYSTROPHY, METACHROMATIC). EC VI: Mucopolysaccharidosis with excessive CHONDROITIN SULFATE B in urine, characterized by dwarfism and deafness. It is caused by a deficiency of N-ACETYLGALACTOSAMINE-4-SULFATASE (arylsulfatase B).Ion Pumps: A general class of integral membrane proteins that transport ions across a membrane against an electrochemical gradient.Testosterone: A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.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.Polymorphism, Genetic: The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.Polymorphism, Restriction Fragment Length: Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.Plasminogen Activator Inhibitor 1: A member of the serpin family of proteins. It inhibits both the tissue-type and urokinase-type plasminogen activators.Tissue Plasminogen Activator: A proteolytic enzyme in the serine protease family found in many tissues which converts PLASMINOGEN to FIBRINOLYSIN. It has fibrin-binding activity and is immunologically different from UROKINASE-TYPE PLASMINOGEN ACTIVATOR. The primary sequence, composed of 527 amino acids, is identical in both the naturally occurring and synthetic proteases.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.Urokinase-Type Plasminogen Activator: A proteolytic enzyme that converts PLASMINOGEN to FIBRINOLYSIN where the preferential cleavage is between ARGININE and VALINE. It was isolated originally from human URINE, but is found in most tissues of most VERTEBRATES.

Effects of sample dilution, peroxidase concentration, and chloride ion on the measurement of unbound bilirubin in premature newborns. (1/113)

OBJECTIVES: To assess the effects of sample dilution, peroxidase concentration, and chloride ion (Cl(-)) on plasma unbound bilirubin (B(f)) measurements made using a commercial peroxidase methodology (UB Analyzer) in a study population of ill, premature newborns. DESIGN AND METHODS: B(f) was measured with a UB Analyzer in 74 samples at the standard 42-fold sample dilution and compared with B(f) measured at a 2-fold sample dilution using a FloPro Analyzer. B(f) was measured at two peroxidase concentrations to determine whether the peroxidase steady state B(f) (B(fss)) measurements were significantly less than the equilibrium B(f) (B(feq)), in which case it was necessary to calculate B(feq) from the two B(fss) measurements. B(f) was also measured before and after adding 100 mmol/L Cl(-) to the UB Analyzer assay buffer. RESULTS: B(feq) at the 42-fold dilution was nearly 10-fold less than but it correlated significantly with B(feq) at the 2-fold dilution (mean 8.2+/-5.2 nmol/L versus 73.5+/-70 nmol/L, respectively, p<0.0001; correlation r=0.6). The two UB Analyzer B(fss) measurements were significantly less than B(feq) in 42 of 74 (57%) samples, and Cl(-) increased B(feq) in 66 of 74 (89%) samples by a mean of 82+/-67%. CONCLUSIONS: B(fss) measured by the UB Analyzer at the standard 42-fold sample dilution using assay buffer without Cl(-) and a single peroxidase concentration is significantly less than the B(feq) in undiluted plasma. Accurate B(f) measurements can be made only in minimally diluted serum or plasma.  (+info)

Isolation of polysome-bound mRNA from solid tissues amenable for RT-PCR and profiling experiments. (2/113)

Using cell lines and primary cells, it has been shown that translation control plays a key role regulating gene expression during physiological and pathological conditions. The relevance of this type of regulation in vivo (tissues, organs) remains to be elucidated, due to the lack of an efficient method for polysome-bound fractionation of solid tissue RNA samples. A simple and efficient method is described, in which tissue samples were pulverized in liquid nitrogen and lysed with NP40-lysis buffer in the presence of the RNAse inhibitors RNAsin and vanadyl-ribonucleoside complex. After cell lysis, the cytoplasmic extract was loaded into sucrose gradients, fractionated, and RNA prepared from each fraction. The obtained RNA was reverse transcribed with a low efficiency, a problem that was overcome by purifying polyA+ RNA. Aiming to use small quantities of solid tissue samples (10-20 mg/sample), polyA+ RNA purification was discarded, and the different components were individually screened for a negative effect on reverse transcription. The polysaccharide heparin, which is present as a nonspecific RNAse inhibitor, inhibits reverse transcriptase activity, and must be removed from RNA samples for an efficient reaction. Heparin was successfully removed by precipitation of the RNA with lithium chloride, as demonstrated by the reversal of the inhibition on RT-PCR reactions. In summary, we present a reliable method allowing us to prepare high-quality polysome-bound mRNA from small quantities of liquid-nitrogen-frozen solid tissue samples from both human and mouse origin, amenable for Northern blotting, RT-PCR reactions, and expression profiling analyses.  (+info)

Metabolism, pharmacokinetics, and excretion of a nonpeptidic substance P receptor antagonist, ezlopitant, in normal healthy male volunteers: characterization of polar metabolites by chemical derivatization with dansyl chloride. (3/113)

The excretion, biotransformation, and pharmacokinetics of ezlopitant [(2-benzhydryl-1-aza-bicyclo[2.2.2]oct-3-yl)-(5-isopropyl-2-methoxy-benzyl)-amine ], a substance P receptor antagonist, were investigated in healthy male volunteers after oral administration of a single 200-mg (approximately 93 microCi/subject) dose of [(14)C]ezlopitant. The total recovery of administered radioactive dose was 82.8 +/- 5.1, with 32.0 +/- 4.2% in the urine and 50.8 +/- 1.4% in the feces. Mean observed maximal serum concentrations for ezlopitant and total radioactivity were achieved at approximately 2 h after oral administration; thus, ezlopitant was rapidly absorbed. Ezlopitant was extensively metabolized in humans, since no unchanged drug was detected in urine and feces. The major pathway of ezlopitant in humans was the result of the oxidation of the isopropyl side chain to form the omega-hydroxy and omega-1-hydroxy (M16) metabolites. M16 and omega,omega-1-dihydroxy (1,2-dihydroxy, M12) were identified as the major circulating metabolites accounting for 64.6 and 15.4% of total circulating radioactivity, respectively. In feces, the major metabolite M14 was characterized as the propionic acid metabolite and formed by further oxidation of the omega-hydroxy metabolite. The urinary metabolites were the result of cleaved metabolites caused by oxidative dealkylation of the 2-benzhydryl-1-aza-bicyclo[2.2.2]oct-3-yl moiety. The metabolites (M1A, M1B, and M4), approximately 34% of the total radioactivity in urine, were identified as benzyl amine derivatives. These were polar metabolites that were further characterized using the reaction with dansyl chloride to derivatize the primary amines and phenol moieties to less polar analytes. The other metabolites were the result of O-demethylation, dehydrogenation of the isopropyl group, and oxidation on the quinuclidine moiety.  (+info)

Arsenic determination in marine sediment using ultrasound for sample preparation. (4/113)

This work deals with As determination in marine sediment using ultrasound for sample preparation. It is shown that As can be quantitatively extracted from marine sediment using 20% (v/v) HCl and sonication. The slurry is centrifuged and the analyte is determined in the supernatant by hydride generation atomic absorption spectrometry (HG AAS). A flow injection (FI) system is employed for hydride generation, with 0.5% (m/v) NaBH(4) used as reducdant and a 20% (v/v) HCl used as sample carrier. The limit of quantification is 1.6 microg g(-1) of As, which is based on 800 microl of sample solution and 0.200 g of sample mass in a volume of 50 mL. Certified and non certified marine sediment samples were analyzed; the results were in accordance with the certified or reference values. Speciation analysis by HPLC-ICP-MS showed that As(V) is the only detectable As species present in the supernatant of the centrifuged sample.  (+info)

On-plate digestion using a commercial microfraction collector for nano-HPLC matrix-assisted laser desorption/ionization tandem time-of-flight protein analysis. (5/113)


Synthesis of bis(amino alcohol)oxalamides and their usage for the preconcentration of trace metals by cloud point extraction. (6/113)

C(2)-Symmetric two bis(amino alcohol)oxalamides (diamidediols) were synthesized and fully characterized. A new method was developed and successfully applied for the simultaneous preconcentration of both trace and toxic metals in water, by using C(2)-symmetric compounds. Under the optimum experimental conditions (i.e. pH = 10.0 +/- 0.2, 2.75 x 10(-3) mol L(-1) N,N'-bis[(1R)-1-ethyl-2-hydroxyethyl]ethanediamide (DAD1), 1.75 x 10(-3) mol L(-1) N,N'-bis[(1S)-1-benzyl-2-hydroxyethyl]-ethanediamide (DAD2), 0.10% w/v octylphenoxy-polyethoxyethanol (Triton X-114)), calibration graphs were linear in the range of 2.5 - 25.0 ng mL(-1) for Cu and Cd, 5.0 - 25.0 ng mL(-1) for Co and Ni. The enrichment factors were 18, 23, 18 and 20 for Cd, Cu, Co and Ni in the case of DAD1, respectively; 20, 22, 17 and 20 for Cd, Cu, Co and Ni in the case of DAD2. The limits of detection for DAD1 were found to be 0.45, 0.50, 1.25 and 0.60 ng mL(-1) for Cd, Cu, Co and Ni, respectively, and for DAD2 were found to be 0.44, 0.25, 0.60 and 1.55 ng mL(-1) for Cd, Cu, Co and Ni, respectively. The developed method was applied to the determination of Cu, Cd, Co and Ni in water samples and certified reference materials with satisfactory results.  (+info)

Triple-phase single-drop microextraction of silver and its determination using graphite-furnace atomic-absorption spectrometry. (7/113)

A new method is described for the determination of silver based on triple-phase microextraction using diethyldithio-carbamate (DDTC) and thioaminophenol. Ag is separated and preconcentrated from the matrix of the sample solution, and finally determined by electrothermal atomic-absorption spectroscopy. The parameters that affect the efficiency were investigated. Under the optimized conditions, a 30-fold preconcentration factor with a detection limit of 0.05 microg L(-1) was achieved. The relative standard deviation was 10% (5 determinations). The developed method was applied to the determination of trace Ag in water samples.  (+info)

Moving known libraries to an addressable array: a site-selective hetero-Michael reaction. (8/113)


  • The purpose of study was to compare the total mercury and methylmercury measurements techniques and detection levels between analytical institutions in two countries using the same elderly human blood samples. (
  • Detection methods are now based on the chemical and physical properties of the molecules being separated, including, but not limited to color, UV absorbance, size, charge, and hydrophobicity. (
  • Rapid detection of pathogens in blood culture bottles by real-time PCR in conjunction with the pre-analytic tool MolYsis. (
  • Aim of this study is the acceleration of detection and identification of bacteria and fungi in blood cultures by molecular methods before positive signalling in an automated system. (
  • Samples were analysed with an eubacterial real-time PCR assay that enables detection of bacterial DNA and simultaneous differentiation of Gram-positive and Gram-negative bacteria. (
  • PCR analysis in conjunction with MolYsis DNA preparation allows rapid detection of pathogens in blood culture samples. (
  • 6. The method of claim 1 , wherein the one or more separated components are bound to or adsorbed to one or more particle set in a binding channel region located downstream of the first detection channel region. (
  • For the detection of HA, samples and standard were first diluted in Tris-buffered saline (TBS) containing 4M urea while for the measurement of NA they were diluted in TBS containing 0.01% Zwittergent as these conditions significantly improved the detection sensitivity. (
  • Advances in EV sample preparation have not kept pace with advances in downstream analytic techniques such as dPCR and NGS, and the full potential of applying analytical methods for genomics and proteomic profiling to the detection of clinically relevant biomarkers shuttled by circulating EVs has yet to be realized. (
  • This includes analytical methods for characterizing active ingredients and contaminants in cannabis, the development of industry laboratory standards, methods of cannabis extraction, as well as cannabis detection for law enforcement purposes. (
  • The detection efficiency in particle accelerators is very high, as such extremely low sigmas are possible simply by measuring more reference standards and/or counting the unknown sample for longer periods of time. (
  • As good as AMS machines are, simultaneous measurements of the 14C modern standard, sample, and blank cannot be done so small shifts up or down in the detection efficiency of the AMS over the course of the run will affect the accuracy of the result, which at times are outside of the smaller quoted sigma values possible. (
  • With overall enhancement in instrument performances ( sensitivity, detection ability, resolving power, throughput, other performance attributes ), sample preparation techniques had no choice but to keep up with these developments and follow the trend. (
  • A new integrated extraction and real-time PCR-based system for the detection of group B streptococci in antepartum screening samples enriched in Lim broth was compared to the CDC-recommended culture method. (
  • While culture-based methods have historically been the gold standard for demonstrating GBS colonization, several recent studies have demonstrated the utility of PCR-based detection as a sensitive and specific alternative ( 1 , 2 , 4 - 6 , 8 , 9 ). (
  • With no user intervention, the system then dispenses the sample into a microfluidic chamber where real-time PCR amplification and detection are performed. (
  • Additionally, analytical methods are included that modify previously used methods to obtain lower detection limits, and/or to improve accuracy and precision. (
  • One of the reported methods used high performance liquid chromatography (HPLC) in conjunction with ultraviolet absorbance detection. (
  • Epigenome-wide asso- epigenetic epidemiology is growing rapidly, facilitated by ciation studies usually start with a quality control step, popular microarray platforms like the Infinium 450K and often involving discarding individual probes or entire EPIC chips, which offer broad coverage and precise quan- samples with too many high detection p values (resulting tification of DNA methylation. (
  • Samples that have been used for other tests before nucleic acid detection testing are at increased risk of contamination. (
  • Wherever possible, nucleic acid detection tests should be performed on dedicated samples or on aliquots taken before other tests are performed. (
  • Where there are specific requirements for the transport and handling of samples for nucleic acid detection, these must be documented and available to referring practitioners and laboratories. (
  • A competitive immunoassay technique is used, which involves pre-incubation of anti-HAV in the sample with HAV antigen in the assay reagent, followed by incubation with a conjugate reagent that contains biotinylated mouse monoclonal anti-HAV antibody and horseradish peroxidase (HRP)-labeled mouse monoclonal anti-HAV antibody. (
  • This consideration requires selecting an instrument and workflow that fits laboratory operations and the requisite analytic specifications of the assay. (
  • Suppositories are important tools for individual therapy, especially in paediatrics, and an instrumental assay method has become necessary for the quality control of dosage units. (
  • The aim of this work was to develop a rapid, effective high-performance liquid chromatography method to assay aminophenazone in extemporaneous suppositories prepared with two different suppository bases, adeps solidus and massa macrogoli. (
  • QIAGEN N.V., a Netherlands holding company, is the leading global provider of Sample & Assay Technologies that are used to transform biological materials into valuable molecular information. (
  • Conclusions: A more complete examination of samples that may be mislabeled, contaminated, or have poor performance due to technical problems will improve downstream analyses and replication of findings. (
  • There were no changes to the lab method, lab equipment, or lab site for this component in the NHANES 2017-2018 cycle. (
  • To maximise plasma temperature (and hence ionisation efficiency) and stability, the sample should be introduced through the central tube with as little liquid (solvent load) as possible, and with consistent droplet sizes. (
  • Our study shows for the first time that large-scale metabolic profiling using GC-TOF MS is suitable for analysis of fresh frozen human tumor samples, and that there is a consistent and significant change in primary metabolism of ovarian tumors, which can be detected using multivariate statistical approaches. (
  • However, a suitable integration method has not yet been established. (
  • The lesson from the current state of bioprocess sensing, particularly of the single-use variety, is that an analytic modality suitable for one industry, or one setting, doesn't necessarily work in another industry or setting. (
  • Se desarrolló y validó un nuevo método analítico para determinar Levetiracetam (LEV) en suero humano utilizando cromatografía líquida de alta resolución (HPLC) con detección de arreglo de diodos. (
  • This has been true for HPLC, a method used extensively in biopharmaceutical discovery and development, but which is encountering all sorts of problems in PAT settings. (
  • If samples are referred to another laboratory for testing, it is the responsibility of the referring laboratory to ensure that the sample conditions outlined above have been met, and to inform that receiving laboratory if they have not been met. (
  • In addition, there must be frequent review and discussion between the compiler and the analytic laboratory to ensure that there is no disparity between the information that is wanted and the information that is provided. (
  • Unless otherwise stated, we refer to measurements made on biologic samples from the parents or the child but not from the fetus. (
  • Beta Analytic does not report standard deviations of less than +/- 30 BP for single measurements since this can lead to a misinterpretation of the accuracy of the results. (
  • The standard-addition method requires multiple measurements for each sample, but can reduce inaccuracies due to interferences and matrix effects. (
  • All important steps of metabolic profiling in drug development and molecular medicine are described in great detail, starting from sample preparation, to determining the measurement details of all analytical platforms, and finally, to discussing the corresponding specific steps of data analysis. (
  • The toolset will synergistically integrate advanced computational methods and visual analytics with data-enabled scientific discovery and innovative experimental techniques to revolutionize our approach to materials science and engineering. (
  • Creativity and innovation are encouraged to obtain the maximum predictive power or insight through computation, data-centric methods, and theory to achieve the goals of DMREF. (
  • The method transformed gene expression ratios into the form of a reference data set on a gene by gene basis. (
  • Hierarchical clustering analysis, density and box plots, and mixture scores with correlation coefficients revealed that the two data sets were well intermingled, indicating that the proposed method minimized the experimental bias. (
  • The transformation method was slightly more effective when a data set with strong homogeneity in the same experimental group was used as a reference data set. (
  • Proposed method is simple but useful to combine several data sets from different experimental conditions. (
  • With this method, biologically useful information can be detectable by applying various analytic methods to the combined data set with increased sample size. (
  • Therefore, it is necessary to investigate new methods that can effectively combine microarray data sets which were derived from different experimental environments, while simultaneously minimizing systematic bias. (
  • Polysaccharide anomeric correlations were tentatively assigned for each plant sample based on standard samples and various literature data. (
  • This study was designed to generate the data necessary for 510(k) submission to the FDA, so the study design, reference method, and evaluation criteria were performed as required by the FDA. (
  • To improve data-analytic and report-writing skills through group project work. (
  • Given ample resources, the preferred method of obtaining data for a food composition data base is to analyse,or have analysed, samples of the particular foods for the desired nutrients. (
  • Given unlimited resources, direct analysis of foods is the preferred method of obtaining food composition data for specific foods of interest. (
  • Generating analytic data for use in a food composition data base consists of several logically distinct steps: sampling foods representative of the population of foods of interest, preparing the samples and performing the analyses, and recording and preparing the final data. (
  • Emphasis will be on the affinity methods utilized specifically for phosphoprotein and phosphopeptide enrichment prior to MS analysis, and on recent applications of these methods in cell biological applications. (
  • Dettmer, Katja , Stevens, Axel Peter , Fagerer, Stephan R , Kaspar, Hannelore und Oefner, Peter J. (2012) Amino acid analysis in physiological samples by GC-MS with propyl chloroformate derivatization and iTRAQ-LC-MS/MS. Methods in molecular biology 828, S. 165-181. (
  • Two mass spectrometry-based methods for the quantitative analysis of free amino acids are described. (
  • The first method uses propyl chloroformate/propanol derivatization and gas chromatography-quadrupole mass spectrometry (GC-qMS) analysis in single-ion monitoring mode. (
  • The role of drug transport and metabolism on gemcitabine cytotoxicity was examined with specific inhibitors, whereas transcription analysis of human equilibrative nucleoside transporter-1 (hENT1), deoxycytidine kinase (dCK), 5′-nucleotidase (5′-NT), cytidine deaminase (CDA), and ribonucleotide reductase subunits M1 and M2 (RRM1 and RRM2) was done by quantitative reverse transcription-PCR in tumor tissue isolated by laser microdissection from surgical or biopsy samples of 102 patients. (
  • The combination of gas chromatography-TOF (GC-TOF)-based analysis with automatical deconvolution techniques has not been used for analysis of human tumor samples, thus far, but only on mouse tissues in obesity-related research ( 12 ). (
  • Following alignment, a consensus strategy for variant selection was employed along with computational linkage to a formal tumor clonality analysis based on visualization and quantitative methods. (
  • In flow cytometric MRD analysis leukemia-associated immunophenotypes (LAIPs) are indentified at diagnosis and applied to follow-up samples. (
  • BETA Analytic's final report includes the individual analysis method, the delivery basis, the material type, and the individual pretreatments applied. (
  • Instrumental methods are usually calibrated with standards that are prepared (or purchased) using a non-instrumental analysis. (
  • Cut your Analysis Costs with this New Sample Prep Technique! (
  • It's an innovative, simple and fast method for the preparation of samples, a crucial step preceding LC/MS/MS or GC/MS/MS analysis. (
  • The methods of hybridization analysis underlie the diagnostics of genetic, cancerous and infectious diseases. (
  • the technology of hybridization analysis gives an opportunity of the multiple use of biochip that decreases expenses upon analyzing samples. (
  • With the new potential for chemometric analysis using the 2D NMR fingerprint, this gel-state method may provide the basis for an attractive approach to providing a secondary screen for selecting biomass lines and for optimizing biomass processing and conversion efficiencies. (
  • Rather, the intention is to identify well-established methods that are used as the standard methods of analysis. (
  • In our labo-ratory, Atomic Absorption Spectrophotometry has been successfully used for the analysis of zinc in biological samples. (
  • Furthermore, quality checks that the lack of a standard format makes their analysis diffi- go beyond to catch other types of problematic samples cult to automate. (
  • SUBSTANCE: method of preparing standard aerosol samples based on a mixture of fine powder containing defined elements is characterised by that a dispersed mixture of mineral, synthetic and biological materials is used, wherein grain size analysis is used to detect presence of said types of simulating materials and content thereof in a real atmospheric suspension in said region as applied to a specific season is determined. (
  • The difference of the contents of the designated elements in the individual instances of the standard samples reduces the accuracy of control of the chemical composition of atmospheric aerosols, which is loaded on the filter, using a variety of spectral and chemical methods of analysis. (
  • This may be replaced by CHEM 671 Instrumental Methods for Chemical Analysis as one of the allowed Level 600 courses as an elective depending on circumstances. (
  • sampling describes how examples of that food are collected for analysis. (
  • 15. The method of claim 14 , further comprising admixing 2,2-dimethyl-1,3-dioxolane-4-methanol and a RSO 2 Y reagent to form the compound of formula (VI), wherein Y is chloride, bromide, or iodide. (
  • G01N1/28 - Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. (
  • All tissue samples were resected specimens obtained from patients undergoing removal of the malignant part of the stomach or the colon. (
  • Specimens are to be collected according to principles outlined below, as sample contamination can occur at any stage of specimen collection and processing. (
  • The procedures used for nucleic acid isolation from the full range of sample types, collection methods (eg patient versus staff collection) and the condition of specimens received by the laboratory must be validated and procedures detailed in the laboratory methods manual. (
  • NHANES uses several methods to monitor the quality of the analyses performed by the contract laboratories. (
  • Routine analyses for the glycol ethers in water, including 2-butoxyethanol and its acetate are often not completed because frequently used general-purpose GC/MS methods designed to measure priority pollutants do not readily detect these compounds (Eckel et al. (
  • RESULTS: Both RT-PCR and MALDI-TOF analyses indicated that the causative agent in both patient samples was L. infantum. (
  • Just, Allan C. 2018-06-01 00:00:00 Background: Mislabeled, contaminated or poorly performing samples can threaten power in methylation microarray analyses or even result in spurious associations. (
  • New tools and methods to provide an improved understanding of tumor clonal architecture are needed to guide therapy. (
  • Whole exome sequencing (WES) on an Illumina HiSeq 2500 was performed on paired tumor and normal samples from a Multiple Myeloma (MM) patient at presentation, then first and second relapse. (
  • MRD in AML can be based on molecular methods (PCR targeting fusion genes, mutations or expression levels of appropriate genes) or on multicolour flow cytometry. (
  • For a second benchmark dataset, we accurately quantify fold changes over several orders of magnitude, a task that is challenging with label-based methods. (
  • This is achieved by ionizing the sample with inductively coupled plasma and then using a mass spectrometer to separate and quantify those ions. (
  • Plasma samples containing YZG-331 and YZG-441 (internal standard, IS) were prepared using a simple protein precipitation by the addition of acetonitrile. (
  • The plasma samples were extracted by protein precipitation using albendazole sulfoxide-d3 as internal standard (IS). (
  • All Beta Analytic clients have 24/7 access to results via their secure online archive. (
  • The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. (
  • One day means results are available 1 day after the sample is received in the laboratory. (
  • The goal of this three-site investigational study was to compare the results obtained by BDM to those obtained by the CDC-recommended culture procedure, which served as the reference method ( 3 ). (
  • Results: Nine hundred forty samples were flagged by at least one control metric and 133 samples from 20 datasets were assigned the wrong sex. (
  • The RAND Postdoctoral Training Program in the Study of Aging enables outstanding junior scholars in demographic and aging research to sharpen their analytic skills, learn to communicate research results effectively, and advance their research agenda. (
  • In these situations, we measure the level of the chemical in another biologic sample to gauge the internal dose. (
  • Under the auspices of the Chemical Exposures Workgroup of the NCS, we developed this article as part of a larger white paper ( NCS 2004 ) to provide guidance on which biologic samples may be most useful for characterizing exposures of interest in the NCS. (
  • While this may produce a very small numerical sigma value, that value is strictly limited to the "determinate errors" associated with counting the 14C modern standard (oxalic acid), unknown sample, and chemical blank (background). (
  • Precipitation: This is a gravimetric method in which the reactants and products of a chemical reaction are used to analyze a substance. (
  • The disadvantage of this approach is a rejection of approximately 5% of instances, with instability on the chemical composition of the remaining individual instances of the standard samples is characterized by a coefficient of variation equal to 4-7% depending on the element being defined. (
  • However, because the quantity of the composite product was limited by the electrochemical method, it is still desirable to synthesize conducting polymer composites with both conducting and ferromagnetic behaviors by a chemical method that can produce larger quantities. (
  • To receive news and publication updates for Computational and Mathematical Methods in Medicine, enter your email address in the box below. (
  • These computational methods include simple additive prescriptions to combine peptide intensities ( 32 , 33 ), reference-peptide-based estimates ( 34 ), and statistical frameworks utilizing additive linear models ( 35 , 36 ). (
  • The methods include the use of a component-binding moiety specific to the component of interest, such as an antibody, to detect the component of interest. (
  • Methods: Quality checks implemented here include 17 control metrics defined by the manufacturer, a sex check to detect mislabeled sex-discordant samples, and both an identity check for fingerprinting sample donors and a measure of sample contamination based on probes querying high-frequency SNPs. (
  • As global requirements for food safety are growing in numbers and complexity, safer, faster and more refined methods are needed to increase efficiency and overall capacity of pesticide residue testing laboratories. (
  • This delicate balancing act of improving quality while maintaining efficiency is the job of process analytic technology (PAT). (