Acid Fast Bacillae Staining Method
The use of acid-fast stain to examine a specimen for the presence of acid-fast microorganisms, specifically mycobacteria.
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The use of acid-fast stain to examine a specimen for the presence of acid-fast microorganisms, specifically mycobacteria.
Explore topicA chromatographic separation technique based on the ability of proteins to bind specific ligands reversibly.
Explore topicA type of electrophoresis that uses a matrix of highly purified agar to separate large molecules.
Explore topicA modified polymerase chain reaction (PCR) technique in which a specific primer can amplify its corresponding allele only; this allows for the determination of the presence or absence of a single, specific allele during genotype testing.
Explore topicA technique designed to rapidly enrich and amplify targets derived from samples that yield low levels of nucleic acids, such as formalin-fixed paraffin-embedded (FFPE) tissues, for use in next-generation sequencing. Briefly, total nucleic acid or genomic DNA (gDNA) is isolated from fresh or FFPE tissues. Total nucleic acid is converted to double-stranded cDNA (dscDNA) and cleaned by solid-phase reversible immobilization (SPRI). Then the dscDNA or gDNA is subjected to end repair, adenylation and ligation with a universal half-functional adapter. The modified DNA sample is then subjected to two rounds of nested low-cycle PCR, where the first round uses target gene-specific primers and the second round uses nested target gene-specific primers that are 5' tagged with a common sequencing adapter. The resulting target amplicon library is cleaned using SPRI and is suitable for use in next generation genomic assays.
Explore topicA molecular cytogenetic method combining chromosomal comparative genomic hybridization technique and microarray to detect chromosomal aberrations and changes in DNA copy numbers in the genome, using oligonucleotides immobilized on a solid support as targets for hybridization.
Explore topicA molecular genetic technique that isolates and sequences chromosomal regions that are rich in open chromatin. First, nuclei are harvested from a cellular sample. Then a hyperactive Tn5 transposase is added to the nuclei where it excises non-nucleosomal DNA strands and ligates co-administered high-throughput sequencing adapters (tagmentation). The tagged DNA fragments are isolated, amplified by PCR and sequenced. The number of reads for specific region of DNA correlate with increased chromatin accessibility and this method can identify regions of transcription factor and nucleosome binding.
Explore topicA spectrometric method that determines the type and concentration of metal elements in a sample, based upon the principle that each elemental metal absorbs a particular wavelength of ultraviolet light when exposed to heat.
Explore topicA technique utilizing a scanning probe to image and analyze the surface of a material with atomic-level resolution.
Explore topicSeveral related technologies for imaging and measuring surfaces on a fine scale, down to the level of molecules and groups of atoms. These technologies share the concept of scanning an extremely sharp tip (3-50 nm radius of curvature) across the object surface. The tip is mounted on a flexible cantilever, allowing the tip to follow the surface profile. When the tip moves in proximity to the investigated object, forces of interaction between the tip and the surface influence the movement of the cantilever. Various interactions can be studied depending on the specific mechanics of the probe. Specialized sensors detect and record the movements of the cantilever, providing an image with resolution at the atomic level.
Explore topicThe production of light by certain living organisms, including fireflies and phytoplankton, by the conversion of chemical to radiant energy.
Explore topicA DNA sequencing technique that can differentiate cytosine from 5-methylcytosine in a DNA sample. First, a denatured DNA sample is treated with bisulfite which converts non-methylated cytosine to uracil. Next, the sample is amplified using a PCR method that does not discriminate between non-methylated and methylated sequences. The amplified DNA is subjected to nucleotide sequencing. The resulting sequence is compared to an identical control sample of DNA that was not treated with bisulfite. Unmethylated cytosines will be displayed as cytosines in the control sample and as thymines in the bisulfite-treated sample.
Explore topicAn electrophoresis procedure, in which a sample is introduced into a capillary tube and the components are separated by the application of high voltage. Due to the large surface to volume ratio, cooling is more efficient, allowing use of higher voltages. As a result, separation occurs more quickly and sensitivity is increased. The technique allows for separation of proteins, nucleic acids, and carbohydrates.
Explore topicGeneral term referring to the maintenance of cell strains or lines in the laboratory.
Explore topicAny of various processes to isolate one or more specific cell populations from a heterogeneous mixture of cells.
Explore topicA process where a rotating machine exposes a specimen to centrifugal force. This process can be used to remove moisture from a specimen, to subject an organism to increased gravitational forces, or to separate the components of heterogeneous mixtures based on density differences.
Explore topicThe emission of light as the result of a chemical reaction.
Explore topicA molecular genetic technique that combines chromatin immunoprecipitation (ChIP) with massively parallel DNA sequencing to map the binding sites of DNA-associated proteins in a sample of cells. First, crosslinked protein-DNA complexes are isolated using ChIP. Next, the crosslinks are broken, the proteins are removed and the purified DNA is modified with adaptor oligonucleotides to facilitate massively parallel DNA sequencing. Following sequencing, the DNA sequences that are obtained can be mapped to their genomic locations.
Explore topicA technique that utilizes immunoprecipitation to find protein-DNA interactions in a biological sample. First, the sample is treated causing the formation of protein-chromatin crosslinks. Then, the sample is sheared to separate individual protein-DNA complexes. Finally, an antibody directed against a protein of interest is applied and the protein-DNA complexes are immunoprecipitated.
Explore topicA laboratory procedure that combines the sequence-specific detection aspects of FISH with the simple detection methods of immunohistochemistry. Briefly, sequence-specific probes are hybridized to cells fixed on slides and the sequestered probe is visualized by a peroxidase reaction. It has the advantage of being a less costly assay that does not require fluorescence microscopy with results that are stable over time.
Explore topicThe treatment of chromosomes to reveal characteristic patterns of horizontal bands. The banding patterns lend each chromosome a distinctive appearance so the 22 pairs of human non-sex chromosomes and the X and Y chromosomes can be identified and distinguished without ambiguity. Banding also permits the recognition of chromosome deletions (lost segments), chromosome duplications (surplus segments) and other types of structural rearrangements of chromosomes.
Explore topicCompare liquid and lyophilized reagent formats by temperature requirement, shipping risk, shelf life, and procurement readiness.
Explore topicAn assessment used to quantify and describe the colors within the visible spectrum of light.
Explore topicComparative genomic hybridization (CGH) is a technique that allows the detection of losses and gains in DNA copy number across the entire genome without prior knowledge of specific chromosomal abnormalities. Comparative genomic hybridization utilizes the hybridization of differentially labeled tumor and reference DNA to generate a map of DNA copy number changes in tumor genomes. Comparative genomic hybridization is an ideal tool for analyzing chromosomal imbalances in archived tumor material and for examining possible correlations between these findings and tumor phenotypes. (from Ried et al. J Mol Med 1997 75:801-14)
Explore topicA type of ELISA assay that uses a reference antigen to competitively bind labeled antibody against an antigen of interest. The strength of the signal interference caused by antibody bound to the reference antigen is used to determine the concentration of the antigen of interest.
Explore topicA system of (usually) epifluorescence light microscopy in which a fine laser beam of light is scanned over the object through the objective lens. The technique is particularly good at rejecting light from outside the plane of focus and so produces higher effective resolution than is normally achieved.
Explore topicElectron microscopy involving an aqueous suspension of a sample which is applied in an extremely thin film to a grid, frozen in liquid nitrogen and maintained in this state by means of a special mount. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.
Explore topicBranch of histochemistry associated with the localization of cellular components by specific staining methods, as for example the localization of acid phosphatases by the Gomori method.
Explore topicTechniques for analysis of chromosomal and subchromosomal properties and structures, such as those to diagnose, classify, screen for, or manage genetic diseases and abnormalities.
Explore topicThe light microscopic study of normal and abnormal cells in fine needle aspirates (FNAs), body cavity fluids, and smears.
Explore topicA light microscopic technique in which the light that does not come into contact with the structures or details of interest is subtracted from the ocular image. This yields an image in which the structures or details are alight while the areas where the structures or details are absent are dark.
Explore topicA method of separating macromolecules by either their differential rate of sedimentation in a centrifugal gradient or their differential buoyancy in a density gradient. (from biology-text.com)
Explore topicA DNA sequencing technique in which a mixture of deoxynucleosidetriphosphates (dNTPs) and chain-terminating dNTPs, which are radioactively or fluorescently labeled, are combined within the reaction mixture. Once the reaction is complete, the DNA strands are separated by size, and the labeled chain terminating dNTPs can be read in sequence by the investigator or by a machine.
Explore topicA type of polymerase chain reaction technique in which the sample is fractionated, within which individual PCR reactions occur in each fraction.
Explore topicA measurement of the antibody or complement-coated erythrocytes in a blood specimen in vivo.
Explore topicIdentification of an individual's genetic information from their DNA.
Explore topicAny method that extracts and purifies DNA from biological samples, which can include the proper handling of biological samples prior to nucleic acid isolation, the separation of DNA from the rest of the components in the samples, and the storage of the DNA isolates.
Explore topicThe determination of the sequence of purines and pyrimidines in deoxyribonucleic acid (DNA).
Explore topicA method in which electromagnetic radiation, in the form of light emission, is generated from an electrochemical reaction in a solution due to the formation of antigen-antibody complexes.
Explore topicAny form of microscopy in which the interactions of electrons with the specimens are used to provide information about the final structure of that specimen.
Explore topicA molecular biology technique used to detect the interaction of a DNA binding protein with its cognate binding sequence. Labeled DNAs were reacted with crude cell extracts and the complexes are run through a non-denaturing polyacrylamide gel. The migration of the labeled DNA through the gel will be slower by being bound. This shift in electrophoretic mobility indicates functional binding between the protein and the DNA.
Explore topicA procedure used in mass spectrometry analysis. Means of delivering nonvolatile analytes into the gas phase for mass analysis. Best used on molecules which are charged in solution or readily accept a charge. Particularly well suited to the analysis of biomolecules. Can be used to probe tertiary structure and non-covalent interactions (from NCSU Mass Spectrometry Facility web site)
Explore topicA highly sensitive technique for detecting and measuring antigens or antibodies in a solution; the solution is run over a surface to which immobilized antibodies specific to the substance have been attached, and if the substance is present, it will bind to the antibody layer, and its presence is verified and visualized with an application of antibodies that have been tagged in some way. (BioTech Life Science Dictionary)
Explore topicAny of several immunoassay methods that use an enzyme covalently linked to an antigen or antibody as a label; the most common types are enzyme-linked immunosorbent assay (ELISA) and enzyme-multiplied immunoassay technique (EMIT).
Explore topicA type of homogenous immunoassay in which sample is applied to a reagent mixture of enzyme-labeled ligand, antibody, and substrate. Substrate binding to enzyme leads to inactivation and unlabeled-ligand in the sample can be quantified by colorimetric analysis.
Explore topicA method to determine microbial susceptibility to antibiotics in which a plastic strip impregnated with the antibiotic of interest is placed on an agar plate that has been inoculated with bacteria. The antibiotic diffuses from the strip producing a concentration gradient of drug on the agar. The point at which the elliptical shaped area of growth inhibition meets the strip is the minimum inhibitory concentration of the drug of interest.
Explore topicThe process of passing a liquid or gas through a filter.
Explore topicA technique for counting, examining and sorting microscopic particles suspended in a stream of fluid.
Explore topicSelection and deposition of individual cells of a particular phenotype from a mixed population into a separate tube or tissue culture plate by the use of a fluorescence-activated cell sorter (FACS) and fluorescently-labeled antibodies specific for surface molecules on the cells to be sorted.
Explore topicA physical mapping approach that uses fluorescent tags to detect hybridization of probes within metaphase chromosomes or less condensed somatic interphase chromatin. This technique can be used for identification of chromosomal abnormalities and for gene mapping.
Explore topicA technique in which samples that either contain fluorescent compounds or are stained with fluorescent dyes are exposed to a wavelength of light that excites the fluorophore, allowing for an image to be captured by a microscope.
Explore topicAn immunoassay in which a fluorescent tracer is used to detect an analyte of interest by triggering the emission of photons when subjected to polarized light.
Explore topicA process to measure the proximity of two fluorochromes whereby the excitation energy of one fluorochrome is released and absorbed by the second fluorochrome. It is used to study interactions and structure of macromolecules. (NCI)
Explore topicFluorescent spectroscopy or fluorometry is a type of electromagnetic spectroscopy used for analyzing fluorescent spectra. It involves using a beam of light, usually ultraviolet light, that excites the electrons in molecules of certain compounds and causes them to emit light of a lower energy, typically, but not necessarily, visible light.
Explore topicAn immunological procedure in which the antibodies are coupled with molecules which fluoresce under ultra violet (UV) light. This makes them particularly suitable for detection of specific antigens in tissues or on cells.
Explore topicUse of Giemsa stain to produce a characteristic staining pattern on chromosomes
Explore topicA chromatographic technique in which the stationary phase is solid while the mobile phase is gaseous samples. The gaseous samples are separated based on their different adsorption ability to the solid phase.
Explore topicAn analytical technique wherein gas chromatography is coupled to mass spectrometry in order to separate, identify, and quantify substances in a sample.
Explore topicGel electrophoresis is a method of separating large molecules (such as DNA fragments or proteins) from a mixture of similar molecules by electrophoretic filtration through a gelatinous matrix. Subject to an electric field, each molecule in the sample mixture migrates through the matrix at a different rate, depending mainly on electrical charge and size, resulting in spatial separation within the matrix of each molecular species in the sample mixture. Agarose and acrylamide in a cylindrical tube or slab gel are commonly used media for electrophoresis of proteins and nucleic acids.
Explore topicGel permeation or sieve chromatography that is performed on porous gels that separate solutes on the basis of size. Smaller solutes are included within the particles of the gel matrix more frequently than larger solutes, thus affecting elution rates.
Explore topicThe process of measuring the extent of crossovers between chromosomes as a gauge of the distance between genes.
Explore topicThis is a method (named after the Danish bacteriologist, Hans Christian Gram) for staining and identifying bacteria. It is based on the differential retention of a crystal violet-iodine complex within the cell membrane. Gram-positive organisms will appear blue-black or purple while Gram-negative organisms will appear red.
Explore topicAn in vitro assay that is used to determine whether antibodies present in serum samples will prevent hemagglutination in a cell culture plate containing red blood cells and influenza virus.
Explore topicHematoxylin-and-eosin, or H&E, is a routine staining procedure of tissue sections. This staining method uses two separate dyes, one staining the nucleus and the other staining the cytoplasm and connective tissue. Hematoxylin is a dark purplish dye that stains the chromatin (nuclear material) within the nucleus. Eosin is an orangish-pink to red dye that stains the cytoplasmic material including connective tissue and collagen.
Explore topicFrequently referred to simply as HPLC, this form of column chromatography is used frequently in biochemistry. The analyte is forced through a column by liquid at high pressure, which decreases the time the separated components remain on the stationary phase. Less time on the column then translates to narrower peaks in the resulting chromatogram and thence to better selectivity and sensitivity.
Explore topicThe study of cells and tissues using chemical staining techniques.
Explore topicThe microscopic study of characteristic tissue abnormalities by employing various cytochemical and immunocytochemical stains.
Explore topicAffinity chromatography using monoclonal or polyclonal antibodies, or (less commonly) antigens, as the immobilized binding phase.
Explore topicA type of chromatography assay in which an antibody-conjugate is passed over an immobilized antigen, giving a visual indication of positive or negative result.
Explore topicA method for the detection of proteins or antigens on samples of cells that are grown in monolayers or in suspension and deposited on slides using antibodies or other biomolecules that bind the target and can be visualized through a chemical process.
Explore topicA quantitative technique used to detect and estimate the concentration of an antigen by measuring the precipitation which is formed as a result of the interaction of the antigen and an antibody at optimal concentration.
Explore topicA laboratory testing method to determine the concentrations of immunoglobulins in the blood.
Explore topicAn enhancement of immunoelectrophoresis in which a series of post-electrophoretic gel slabs are layered with cellulose-acetate gels saturated with specific antibodies. The resulting antigen-antibody complexes fixed on the second gel may then be stained, allowing sensitive and specific qualitative visual identification of paraproteins by electrophoretic position. It can be used to identify specific proteins in the blood or urine. It has greatest application in the identification and monitoring of monoclonal proteins that are produced in conditions like Waldenstom's macroglobulinaemia and multiple myeloma.
Explore topicImmunohistochemical staining techniques allow for the visualization of antigens via the sequential application of a specific antibody to the antigen (primary antibody), a secondary antibody to the primary antibody and an enzyme complex with a chromogenic substrate. The enzymatic activation of the chromogen results in a visible reaction product at the antigen site. The specimen may then be counterstained and coverslipped. Results are interpreted using a light microscope and aid in the differential diagnosis of pathophysiological processes, which may or may not be associated with a particular antigen.
Explore topicLaboratory test involving interaction of antigens with specific antibodies.
Explore topicAn immunological procedure in which antibodies are coupled with a peroxidase molecule. Following localization via the antibody, the peroxidase is reacted with a corresponding substrate to produce a product which can be seen with a light microscope.
Explore topicAntigen aggregation with antibody, in the right ratios, to cause precipitation.
Explore topicUse of a DNA or RNA probe to detect the presence of complementary sequences in chromosomes, cells, or tissues.
Explore topicA test that uses Coombs' reagent to detect the presence of anti-erythrocyte antibodies in serum.
Explore topicA mass spectrometry technique that uses inductively-coupled plasma generated from argon gas to atomize and ionize a sample. The resulting ions are separated and analyzed using a mass spectrometer.
Explore topicReview fluorescence channels, protocol fit, reaction format support, and analysis software before switching assays or entering procurement comparison.
Explore topicUse control design and QC workflow planning to reduce false negatives, monitor inhibition, and improve documentation readiness.
Explore topicA type of gel electrophoresis in which charged molecules travel through a pH gradient. The molecules will come to stop at the point where the net charge on the molecule is equal to that of the surrounding gel.
Explore topicThe preparation, analysis, and interpretation of a karyotype, the representation of the chromosome set of a cell.
Explore topicA high-resolution method used to isolate cells from their surrounding tissues, with the aid of a laser beam, under direct microscopic visualization. Specific cells can be isolated directly by cutting target cells away from unwanted cells, to obtain enriched cell populations.
Explore topicLight Microscopy is a technique for producing visible images of structures or details which are too small to be otherwise seen by the human eye. It involves passing light transmitted through or reflected from the subject through a series of lenses to be detected directly by the eye, imaged on a photographic plate, or captured digitally.
Explore topicA type of chromatography in which separation of a mixture is achieved by passing a sample in a stream of liquid solvent through some form of material that will provide resistance by virtue of chemical interactions between the components of the sample and the material.
Explore topicLC/MS is a hyphenated technique, combining the separation power of liquid chromatography (LC), an analytical chromatographic technique for separating ions or molecules dissolved in a solvent, with the detection power of mass spectrometry(MS), a technique to separate gas phase ions according their m/z (mass to charge ratio) value. Used for drug screening, pharmacology studies, environmental analyses and forensics.
Explore topicAn analytical technique wherein liquid chromatography is coupled to tandem mass spectrometry in order to separate, identify, and quantify substances in a sample.
Explore topicInterpret analytical sensitivity, repeatability, reproducibility, and evidence strength before using performance claims in validation or tenders.
Explore topicA type of nucleic acid amplification test in which sample DNA is exposed to a single temperature in the presence of multiple sets of primers and a polymerase with replication and high strand displacement activity. This test negates the need for thermal cyclers and may be a low cost alternative to PCR.
Explore topicAn analysis done to detect monoallelic loss of genes or DNA regions in a diploid cell.
Explore topicA cell-separation technique where magnetizable microspheres or beads are first coated with monoclonal antibody, allowed to search and bind to target cells, and are then selectively removed when passed through a magnetic field. Among other applications, the technique is commonly used to remove tumor cells from the marrow of patients who are to undergo autologous bone marrow transplantation.
Explore topicA flow cytometry technique that utilizes mass spectrometry to detect antibodies labeled with heavy metal ion tags that are bound to antigens of interest on single cells.
Explore topicAn analytical technique wherein ions are separated according to their ratio of charge to mass. From the mass spectrum produced, the atomic weight of the particle can be deduced.
Explore topicAn analysis of DNA or protein to detect the presence and/or location of methyl groups.
Explore topicAnalysis using microarray technology (e.g., cDNA arrays to see gene expression or protein microarrays to profile the pattern of proteins).
Explore topicA laboratory method in which the tissue from a histology slide is dissected under a microscope to procure specific cells or cell populations.
Explore topicA type of enzyme immunoassay that uses antigen-coated microparticles as a substrate for antibody binding.
Explore topicA laboratory procedure to detect microsatellite instability.
Explore topicA laboratory test to determine the lowest concentration of a substance that will inhibit a biological or biochemical function, such as microorganism growth or enzymatic activity.
Explore topicStudies of chromosome biology and behavior at the molecular level.
Explore topicAn imaging technique that uses multiple photons to absorb infrared light, thereby minimizing phototoxicty and photobleaching, making it an ideal method for imaging living specimens, especially those involving deep tissue.
Explore topicA type of high-throughput, multiplex PCR method used to determine abnormal DNA copy number changes of up to 50 genomic DNA or RNA sequences with a single pair of PCR primers. It is frequently used in the detection of genetic aberrations in tumors, and can distinguish sequences differing in only a single nucleotide.
Explore topicCompare panel breadth, sensitivity balance, cross-reactivity, and compatibility before choosing singleplex, low-plex, or high-plex strategies.
Explore topicA proprietary next-generation DNA sequencing technology from Oxford Nanopore Technologies that can directly identify and sequence a DNA molecule as it passes through a nanopore, driven by electrophoresis.
Explore topicA method to quantify the concentration of particulate matter suspended in a liquid or gas using a nephelometer.
Explore topicPolymerase chain reaction that uses two sets of primers, in two sequential runs of amplification, with the second set intended to amplify a target within the first run product.
Explore topicTechnologies that facilitate the rapid determination of the nucleotide sequence of large numbers of strands or segments of DNA or RNA.
Explore topicA technique that determines the nucleotide sequence of a pre-specified region of DNA or RNA by using primers that are specific for that region.
Explore topicA common molecular biology procedure for detection of RNA molecules. RNA extracted from a sample was denatured and separated by slab gel electrophoresis, then blotted on to a nitrocellulose or nylon sheet and hybridized with labeled DNA or RNA that is complementary to the desired RNA, whose presence is subsequently indicated by autoradiography or other visualization techniques.
Explore topicDetection and measurement of the resonant spectra of molecular species in a tissue or sample.
Explore topicCompare magnetic bead, column-based, manual, and automated extraction methods by sample type, inhibitor removal, and downstream PCR fit.
Explore topicMeasuring the optical density of a substance by shining light on it and measuring its transmission.
Explore topicA DNA sequencing strategy where a single read is initiated from each end of a DNA fragment.
Explore topicA method for collecting tandem mass spectrometry data where an ion of a particular mass is selected in the first stage and a fragmented ion product is selected in the second mass spectrometer stage for detection. Parallel reaction monitoring (PRM)-based experiments are generally performed in a high-resolution hybrid quadrupole-Orbitrap (Q-OT) or time-of-flight mass spectrometer.
Explore topicCompare automation levels by hands-on time, staffing pressure, contamination risk, and deployment fit before moving into system-level evaluation.
Explore topicThis is an all-round useful stain for many things, including glycogen, mucin, mucoprotein, glycoprotein, as well as fungi. The reaction is based on the oxidation of glycol group to aldehydes by periodate. The schiff's reagent selectively stains the aldehydes to a rose pink color. PAS is useful for outlining tissue structures--basement membranes, capsules, blood vessels, etc.
Explore topicA simple non-quantitative form of interference microscopy of great utility in visualising live cells. Small differences in optical path length due to differences in refractive index and thickness of structures are visualised as differences in light intensity.
Explore topicA type of spectroscopy that utilizes a laser beam to irradiate a sample containing particles in suspension, resulting in light scattering. Rapid fluctuations in scattering intensity, around a mean value at a certain angle, occur because of particle diffusion and are dependent upon on particle size. The calculated correlation function yields a diffusion coefficient, for a given temperature and viscosity, which can be used to calculate particle size.
Explore topicA serological test that measures the ability of antibodies in specific concentrations of serum to prevent the formation of plaques in a cell monolayer when combined with a viral suspension.
Explore topicAn assay performed to assess platelet clumping, often with the addition of agonists.
Explore topicAnalytical and separative procedures in which molecules, particularly proteins or nucleic acids, are separated by their different electrophoretic mobilities in a hydrated gel. The gel suppresses convective mixing of the fluid phase through which the electrophoresis takes place and contributes molecular sieving. For proteins, commonly carried out in the presence of the anionic detergent sodium dodecylsulphate (SDS). SDS denatures proteins so that noncovalently associating sub unit polypeptides migrate independently and by binding to the proteins confers a net negative charge roughly proportional to the chain weight.
Explore topicA method for amplifying a DNA base sequence using multiple rounds of heat denaturation of the DNA and annealing of oligonucleotide primers complementary to flanking regions in the presence of a heat-stable polymerase. This results in duplication of the targeted DNA region. Newly synthesized DNA strands can subsequently serve as additional templates for the same primer sequences, so that successive rounds of primer annealing, strand elongation, and dissociation produce rapid and highly specific amplification of the desired sequence. PCR also can be used to detect the existence of the defined sequence in a DNA sample.
Explore topicAnalysis that looks for differences in the lengths of microsatellite repeats between alleles. Polymorphic microsatellites are present in the genome every few thousand base pairs and can function as molecular markers.
Explore topicAn electroanalytical technique in which the electrical potential of a solution is measured to determine the composition of the sample, by comparing the constant potential of the reference electrode with the actual potential of the indicator electrode.
Explore topicSeparation of protein fractions by precipitation, chromatography, or other methods.
Explore topicThe process of determining the sequence of amino acids within a protein molecule.
Explore topicPulsed-field gel electrophoresis (PFGE) is a method used to separate proteins or high molecular weight linear DNA fragments that are greater than 50 kilobases (kb) in size. Fragments are separated by pulsing an electrical field across an agarose gel rather than applying the constant field used in conventional electrophoresis.
Explore topicA DNA sequencing method that uses a "sequencing by synthesis" strategy. The strand complementary to a template is synthesized a single base at a time through the sequential addition of individual solutions of each base. Incorporation of a base into the growing strand generates free pyrophosphate that is detected as light, as generated by a luciferase-catalyzed reaction.
Explore topicQuantitative PCR: a method to measure very small amounts of RNA transcripts as cDNA targets. There are two strategies currently used, one is called Competitive RTPCR and the other is called Real-Time PCR.
Explore topicA quantitative technique used to detect and estimate the concentration of an antigen by measuring the diameter of the ring of precipitation (precipitin ring), which is formed as a result of the interaction of the antigen and an antibody at optimal concentration.
Explore topicRadioimmunoassay (RIA) is an immunological technique, which quantitatively determines antigen and antibody concentrations, using a radioactively labeled substance (radioligand), either directly or indirectly.
Explore topicEmission of electromagnetic energy with a shorter frequency (longer wavelength) than that of the incident monochromatic light. Arises from the low probability absorption of quanta with a higher energy than that required for a transition: the difference in energy is emitted as a lower frequency (energy) photon. Allows analysis of vibrational and rotational energy levels using visible incident light.
Explore topicA procedure for amplification of nucleic acid sequences from a messenger RNA template between a defined internal site and unknown sequences at either the 3'- or 5'-end of the mRNA.
Explore topicAn application of PCR that measures the products generated during each cycle of the polymerase chain reaction process in order to determine the starting amount of template in the reaction.
Explore topicA method to measure the refractive index (propensity for light to bend) of a sample.
Explore topicVariation occurring within a species in the length of DNA fragments generated by a specific endonuclease. Such variations are generated by mutations that create or abolish recognition sites for these enzymes.
Explore topicA laboratory procedure in which an RNA strand is first transcribed into a DNA complement and then subjected to PCR amplification. Transcribing an RNA strand into a DNA complement is termed reverse transcription and is done by the enzyme reverse transcriptase.
Explore topicTechnique of electron microscopy in which the specimen is coated with heavy metal and then scanned by an electron beam. The resolution is not as great as with transmission electron microscopy, but preparation is easier (often by fixation followed by critical point drying), the depth of focus is relatively enormous, the surface of a specimen can be seen (though not the interior unless the specimen is cracked open) and the image is aesthetically pleasing.
Explore topicA method for collecting tandem mass spectrometry data where an ion of a particular mass is selected in the first stage and a fragmented ion product is selected in the second mass spectrometer stage for detection. Selected reaction monitoring (SRM)-based experiments are generally performed in a triple quadrupole (QqQ) mass spectrometer.
Explore topicThe process of arranging protein, DNA or RNA sequences to identify regions with similar sequences that may elucidate functional, structural, or evolutionary relationships between the sequences.
Explore topicUnordered sequencing. Unmapped clones spanning a region of interest are sequenced and then assembled into a continuous sequence.
Explore topicSilver Staining or GMS staining is a technique for demonstrating fungi in tissue sections. It is primarily based on staining the polysaccharides in fungal cell wall (From BioGenex).
Explore topicA rapid, simple, visual and sensitive technique for measuring DNA breakage in individual mammalian cells in response to a test agent. A cell is immobilized in agarose and made permeable and the broken DNA migrates out under the influence of the electric field. A damaged cell has the appearance of a comet with a brightly fluorescent cell body and a tail whose length and fluorescence intensity are related to the number of DNA-strand breaks induced by the test agent.
Explore topicA procedure that can determine the nucleotide sequence for all of the RNA transcripts in an amplified nucleotide sample that was derived from a single cell.
Explore topicSodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis is a procedure for estimating molecular weights of polypeptides, and uses SDS, a detergent that dissociates and unfolds oligomeric proteins into its subunits. The SDS binds to the polypeptides to form complexes with fairly constant charge to mass ratios. The electrophoretic migration rate through a gel is therefore determined only by the size of the complexes.
Explore topicA technique for the detection of specific DNA fragments that have been separated by polyacrylamide-gel electrophoresis, transferred to a nitrocellulose or other type of paper or nylon membrane, and detected by hybridization and visualization with a labeled probe.
Explore topicA novel karyotyping procedure which is based on the simultaneous hybridization of 24 chromosome-specific painting probes labeled with different fluorochromes or fluorochrome combinations. The measurement of defined emission spectra by means of interferometer-based spectral imaging allows for the definitive discernment of all human chromosomes in different colors. (from Schrock et al., Hum Genet 1997:101:255-62)
Explore topicA laboratory test that produces a quantitative measurement of the reflection or transmission properties of a material as a function of wavelength.
Explore topicA procedure used to demonstrate nucleotide sequence variations that occur in the same region of DNA between individuals within a species, or between alleles in an individual to detect mutations in various genes, such as oncogenes, tumor suppressor genes, or genes responsible for genetic diseases. The method detects different conformations adopted by partially denatured DNA fragments resulting from their specific nucleotide sequences under denaturing conditions. Denatured single-stranded DNA fragments are allowed to partially renature without formation of double-stranded DNA. The particular conformations adopted by each of the renatured fragments depend on each of their specific nucleotide sequences. The fragments are run on polyacrylamide gels to detect subtle changes in migration due to their particular secondary structures. Resulting fragment band in the gel will misalign if any point mutations are present to alter the conformation.
Explore topicAn isothermal, in vitro nucleic acid amplification method that allows primer-directed amplification of a target sequence. It utilizes a primer that can be nicked to create a polymerase start site and a DNA polymerase that will displace a downstream strand as it tracks along the template.
Explore topicA quantum optical-electrical phenomena consisting of an alteration in light reflectance as a result of binding of molecules to a surface from which total internal reflection is occurring. Used to detect macromolecular interactions, SPR can be used as the basis for a sensor which is capable of sensitive and quantitative measurement of a broad spectrum of chemical and biological entities.
Explore topicMass spectrometers coupled in series. The targeted compound is selectively ionized, and its characteristic ions are separated from others in the mixture in the first mass spectrometer. The selected primary ions are then decomposed by collision, and from the resulting products the final mass analyzer selects secondary ions characteristic of the targeted compound. Tandem mass spectrometry can achieve specificities and sensitivities equivalent of those of methods such as radioimmunoassay and gas chromatography/mass spectrometry, while performing analyses in much shorter times.
Explore topicTranslate daily volume, turnaround targets, staffing, and automation fit into a practical PCR workflow model instead of overbuilding capacity.
Explore topicA method for determining the mass-to-charge ratio (m/z) of gas-phase ions based on measuring how quickly they travel a known distance in an electric field of known strength.
Explore topicA potency unit defined as a minimal dose of infectious material at which preparation causes cytopathic effects (changes in the morphology and metabolism of tissue culture cells, indicating cell death, due to suspected infection) in the 50% of the tissue culture-containing flasks inoculated with that dilution of infectious material in the product potency assay or pathogen activity assay.
Explore topicA technique used to selectively replicate nucleic acid sequences from RNA templates using reverse transcriptase and RNA polymerase. Reverse transcriptase generates cDNA from the region of interest using primers and then RNA polymerase generates copies of the original RNA template.
Explore topicAn electron microscopy imaging technique that is utilized to examine structural components of a sample by passing electrons through the specimen.
Explore topicA method to quantify the opaqueness of a liquid using a turbidimeter, by measuring the decrease in light intensity due to the scattering effect of suspended particles in the liquid sample.
Explore topicA laboratory procedure in which proteins are first separated across a gel, usually polyacrylamide, according to their isoelectric point, and then separated in a perpendicular direction on the basis of their molecular weight.
Explore topicTechnology that detects differences between an individual's DNA sequence and a reference DNA sequence.
Explore topicA diagnostic procedure to identify and characterize a viral organism.
Explore topicA laboratory procedure for the detection or identification of proteins or peptides that have been separated by gel electrophoresis and transferred onto nitrocellulose or other type of paper or nylon membrane. The proteins are then detected by reaction with enzymatically labeled or radiolabeled antibody probes.
Explore topicA procedure that can determine the DNA sequence for all of the exons in an individual.
Explore topicAny technique designed to amplify a limited genomic DNA sample so as to generate a new sample that is indistinguishable from the original but with a higher DNA concentration.
Explore topicA procedure that can determine the DNA sequence for nearly the entire genome of an individual.
Explore topicA procedure that can determine the nucleotide sequence for all of the RNA transcripts in an individual.
Explore topicTools
Planning guide for assay-to-instrument matching across channels, formats, and validation scope.
Open tool briefPlanning guide for translating sample type into extraction, workflow, QC, and buyer-guide next steps.
Open tool briefPlanning guide for converting throughput assumptions into workflow, staffing, and automation planning decisions.
Open tool brief