Laboratory Procedure

MeSH ID: T059

Related Concepts:

  • 2D Polyacrylamide Gel Electrophoresis [M0023334]
  • Activation Analysis [M0000305]
    A method of chemical analysis based on the detection of characteristic radionuclides following a nuclear bombardment. It is also known as radioactivity analysis. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Adsorption [M0000503]
    The condensation of gases, liquids, or dissolved substances on the surfaces of solids. It includes adsorptive phenomena of bacteria and viruses as well as of tissues treated with exogenous drugs and chemicals.
  • Agar Dilution Count [M0023311]
  • Agglutination Tests [M0000570]
    Tests that are dependent on the clumping of cells, microorganisms, or particles when mixed with specific antiserum. (From Stedman, 26th ed)
  • AIDS Serodiagnosis [M0023854]
    Immunologic tests for identification of HIV (HTLV-III/LAV) antibodies. They include assays for HIV SEROPOSITIVITY and HIV SERONEGATIVITY; (ELISA, immunofluorescence, immunoblot, etc.) that have been developed for screening persons carrying the viral antibody from patients with overt symptoms of AIDS or AIDS-RELATED COMPLEX.
  • analysis [M0030237]
    Used for the identification or quantitative determination of a substance or its constituents and metabolites; includes the analysis of air, water, or other environmental carrier. It excludes the chemical analysis of tissues, tumors, body fluids, organisms, and plants for which "chemistry" is used. The concept applies to both methodology and results. For analysis of substances in blood, cerebrospinal fluid, and urine the specific subheading designating the fluid is used.
  • Analytic Sample Preparation Methods [M0490634]
    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.
  • Anti-Human Globulin Complement-Dependent Cytotoxicity Tests [M0005627]
  • Antibiogram [M0490512]
    Pie chart displaying the sensitivity of a set of microbes to one agent or condition.
  • Antibodies, Antinuclear [M0001488]
    Autoantibodies directed against various nuclear antigens including DNA, RNA, histones, acidic nuclear proteins, or complexes of these molecular elements. Antinuclear antibodies are found in systemic autoimmune diseases including systemic lupus erythematosus, Sjogren's syndrome, scleroderma, polymyositis, and mixed connective tissue disease.
  • Antibody Dissociation [M0011160]
  • Antibody Enzyme Technique, Unlabeled [M0011096]
  • Antibody-Coated Bacteria Test, Urinary [M0001369]
    Fluorescent antibody technique for visualizing antibody-bacteria complexes in urine. The presence or absence of antibody-coated bacteria in urine correlates with localization of urinary tract infection in the kidney or bladder, respectively.
  • Aspirin Tolerance Test [M0002651]
  • assay [M0030238]
  • Autoanalysis [M0001984]
  • Autoradiography [M0002018]
    The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)
  • Bacterial Count [M0023312]
  • Bacterial Sensitivity Tests [M0013762]
  • Bacterial Typing [M0023677]
  • Bacterial Typing Techniques [M0023674]
    Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.
  • Bacteriocin Typing [M0023675]
  • Bacteriological Techniques [M0002137]
  • Bacteriophage Typing [M0002140]
    A technique of bacterial typing which differentiates between bacteria or strains of bacteria by their susceptibility to one or more bacteriophages.
  • Basophil Degranulation Test [M0023916]
    An in vitro test used in the diagnosis of allergies including drug hypersensitivity. The allergen is added to the patient's white blood cells and the subsequent histamine release is measured.
  • Biological Assay [M0002520]
    A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.
  • Biosensing Techniques [M0023678]
    Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.
  • Biotinylation [M0029596]
    Incorporation of biotinyl groups into molecules.
  • Biotyping, Bacterial [M0023676]
  • Biotyping, Mycological [M0025234]
  • Biuret Reaction [M0002622]
    A reaction characterized by a violet color upon the addition of copper sulfate to all compounds with two amide or peptide bonds linked directly or through an intermediate carbon atom. Used in the detection and estimation of proteins and peptides having more than two amino acids.
  • Blastocyst Culture Techniques [M0459939]
  • Blood Chemical Analysis [M0002678]
  • Blood Coagulation Tests [M0002685]
    Laboratory tests for evaluating the individual's clotting mechanism.
  • Blood Count, Complete [M0002675]
  • Blood Gas Analysis [M0002690]
    Measurement of oxygen and carbon dioxide in the blood.
  • Blood Grouping and Crossmatching [M0002698]
    Testing erythrocytes to determine presence or absence of blood-group antigens, testing of serum to determine the presence or absence of antibodies to these antigens, and selecting biocompatible blood by crossmatching samples from the donor against samples from the recipient. Crossmatching is performed prior to transfusion.
  • Blood Protein Electrophoresis [M0002709]
    Electrophoresis applied to blood proteins.
  • Blood Sedimentation [M0002714]
    Measurement of rate of settling of erythrocytes in anticoagulated blood.
  • Blood Typing [M0002699]
  • Blood Urea Nitrogen [M0002724]
    The urea concentration of the blood stated in terms of nitrogen content. Serum (plasma) urea nitrogen is approximately 12% higher than blood urea nitrogen concentration because of the greater protein content of red blood cells. Increases in blood or serum urea nitrogen are referred to as azotemia and may have prerenal, renal, or postrenal causes. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
  • Blood Volume Determination [M0002729]
    Method for determining the circulating blood volume by introducing a known quantity of foreign substance into the blood and determining its concentration some minutes later when thorough mixing has occurred. From these two values the blood volume can be calculated by dividing the quantity of injected material by its concentration in the blood at the time of uniform mixing. Generally expressed as cubic centimeters or liters per kilogram of body weight.
  • Blotting, Far-Western [M0378333]
    A method that is derived from western blotting (BLOTTING, WESTERN) and is used to detect protein-protein interactions. The blotted proteins are probed with a non-antibody protein which can then be tagged with a labeled antibody.
  • Blotting, Northern [M0023295]
    Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
  • Blotting, Southern [M0023274]
    A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
  • Blotting, Southwestern [M0378350]
    A method that is used to detect DNA-protein interactions. Proteins are separated by electrophoresis and blotted onto a nitrocellulose membrane similar to Western blotting (BLOTTING, WESTERN) but the proteins are identified when they bind labeled DNA PROBES (as with Southern blotting (BLOTTING, SOUTHERN)) instead of antibodies.
  • Blotting, Western [M0023296]
    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.
  • Bone Demineralization Technique [M0028106]
    Removal of mineral constituents or salts from bone or bone tissue. Demineralization is used as a method of studying bone strength and bone chemistry.
  • Bone Marrow Examination [M0002789]
    Removal of bone marrow and evaluation of its histologic picture.
  • Calorimetry [M0003223]
    The measurement of the quantity of heat involved in various processes, such as chemical reactions, changes of state, and formations of solutions, or in the determination of the heat capacities of substances. The fundamental unit of measurement is the joule or the calorie (4.184 joules). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Calorimetry, Differential Scanning [M0003224]
    Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.
  • Calorimetry, Indirect [M0003225]
    Calculation of the energy expenditure in the form of heat production of the whole body or individual organs based on respiratory gas exchange.
  • CD4 Lymphocyte Count [M0028130]
    The number of CD4-POSITIVE T-LYMPHOCYTES per unit volume of BLOOD. Determination requires the use of a fluorescence-activated flow cytometer.
  • Cell Array Analysis [M0455902]
  • Cell Culture Techniques [M0028299]
    A technique for maintaining or growing CELLS in vitro. Cultures of dispersed cells derived directly from fresh TISSUES are called primary cell cultures. Cultures may also derive from established CELL LINE usually stored frozen.
  • Cell Fractionation [M0003755]
    Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.
  • Cell Migration Inhibition [M0003761]
    Phenomenon of cell-mediated immunity measured by in vitro inhibition of the migration or phagocytosis of antigen-stimulated leukocytes or macrophages. Specific assays have been developed to estimate levels of migration inhibitory factor, immune reactivity against tumor-associated antigens, and immunosuppressive effects of infectious microorganisms.
  • Cell Separation [M0003769]
  • Centrifugation [M0003810]
    Process of using a rotating machine to generate centrifugal force to separate substances of different densities, remove moisture, or simulate gravitational effects. It employs a large motor-driven apparatus with a long arm, at the end of which human and animal subjects, biological specimens, or equipment can be revolved and rotated at various speeds to study gravitational effects. (From Websters, 10th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Centrifugation, Density Gradient [M0003811]
    Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Centrifugation, Isopycnic [M0003812]
    A technique used to separate particles according to their densities in a continuous density gradient. The sample is usually mixed with a solution of known gradient materials and subjected to centrifugation. Each particle sediments to the position at which the gradient density is equal to its own. The range of the density gradient is usually greater than that of the sample particles. It is used in purifying biological materials such as proteins, nucleic acids, organelles, and cell types.
  • Centrifugation, Zonal [M0003813]
    Centrifugation using a rotating chamber of large capacity in which to separate cell organelles by density-gradient centrifugation. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • chemical analysis [M0030239]
  • Chemical Fractionation [M0008800]
    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)
  • Chemiluminescent Measurements [M0464477]
    Measurement of light resulting from PHYSICAL CHEMILUMINESCENCE such as from LUMINESCENT PROTEINS and LUMINESCENT AGENTS.
  • Chromatography [M0004372]
    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, Affinity [M0004373]
    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)
  • Chromatography, Agarose [M0004374]
    A method of gel filtration chromatography using agarose, the non-ionic component of agar, for the separation of compounds with molecular weights up to several million.
  • Chromatography, DEAE-Cellulose [M0004375]
    A type of ion exchange chromatography using diethylaminoethyl cellulose (DEAE-CELLULOSE) as a positively charged resin. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Chromatography, Gas [M0004376]
    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.
  • Chromatography, Gas-Liquid [M0004377]
  • Chromatography, Gas-Liquid-Mass Spectrometry [M0495871]
  • Chromatography, Gel [M0004378]
    Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.
  • Chromatography, High Pressure Liquid [M0004379]
    Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
  • Chromatography, Ion Exchange [M0004380]
    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.
  • Chromatography, Liquid [M0004381]
    Chromatographic techniques in which the mobile phase is a liquid.
  • Chromatography, Micellar Electrokinetic Capillary [M0030012]
    A hybrid separation technique combining both chromatographic and electrophoretic separation principles. While the method was invented to separate neutral species, it can also be applied to charged molecules such as small peptides.
  • Chromatography, Paper [M0004382]
    An analytical technique for resolution of a chemical mixture into its component compounds. Compounds are separated on an adsorbent paper (stationary phase) by their varied degree of solubility/mobility in the eluting solvent (mobile phase).
  • Chromatography, Size Exclusion [M0408252]
    A technique for separating molecules based on molecular size. The solid phase commonly consists of porous beads packed in a column.
  • Chromatography, Supercritical Fluid [M0376478]
    A CHROMATOGRAPHY method using supercritical fluid, usually carbon dioxide under very high pressure (around 73 atmospheres or 1070 psi at room temperature) as the mobile phase. Other solvents are sometimes added as modifiers. This is used both for analytical (SFC) and extraction (SFE) purposes.
  • Chromatography, Thin Layer [M0004383]
    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)
  • Chromosome Banding [M0004409]
    Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.
  • Chromosome Mapping [M0004413]
    Any method used for determining the location of and relative distances between genes on a chromosome.
  • Chromosome Painting [M0029899]
    A technique for visualizing CHROMOSOME ABERRATIONS using fluorescently labeled DNA probes which are hybridized to chromosomal DNA. Multiple fluorochromes may be attached to the probes. Upon hybridization, this produces a multicolored, or painted, effect with a unique color at each site of hybridization. This technique may also be used to identify cross-species homology by labeling probes from one species for hybridization with chromosomes from another species.
  • Circular Dichroism [M0004502]
    A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Circular Dichroism, Vibrational [M0398269]
  • Cis Test [M0009123]
  • Cis-Trans Test [M0009124]
  • Clinical Chemistry Tests [M0029641]
    Laboratory tests demonstrating the presence of physiologically significant substances in the blood, urine, tissue, and body fluids with application to the diagnosis or therapy of disease.
  • Cloning, Molecular [M0004616]
    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.
  • Clot Retraction [M0004640]
    Retraction of a clot resulting from contraction of PLATELET pseudopods attached to FIBRIN strands. The retraction is dependent on the contractile protein thrombosthenin. Clot retraction is used as a measure of platelet function.
  • Co-Immunoprecipitation [M0457741]
  • Coculture Techniques [M0028289]
    A technique of culturing mixed cell types in vitro to allow their synergistic or antagonistic interactions, such as on CELL DIFFERENTIATION or APOPTOSIS. Coculture can be of different types of cells, tissues, or organs from normal or disease states.
  • Colony Count, Microbial [M0023313]
    Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. Each colony (i.e., microbial colony-forming unit) represents the progeny of a single cell in the original inoculum. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.
  • Colony-Forming Units Assay [M0004821]
    A cytologic technique for measuring the functional capacity of stem cells by assaying their activity.
  • Colorimetry [M0004837]
    Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Complement Fixation Tests [M0004919]
    Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.
  • Complement Hemolytic Activity Assay [M0024386]
    A screening assay for circulating COMPLEMENT PROTEINS. Diluted SERUM samples are added to antibody-coated ERYTHROCYTES and the percentage of cell lysis is measured. The values are expressed by the so called CH50, in HEMOLYTIC COMPLEMENT units per milliliter, which is the dilution of serum required to lyse 50 percent of the erythrocytes in the assay.
  • Conductometry [M0004993]
    Determination of the quantity of a material present in a mixture by measurement of its effect on the electrical conductivity of the mixture. (Webster, 3d ed)
  • Conglutinating Complement Absorption Test [M0004920]
  • Coombs' Test [M0005148]
    Hemagglutination test in which Coombs' reagent (antiglobulin, or anti-human globulin rabbit immune serum) is added to detect incomplete (non-agglutinating, univalent, blocking) antibodies coating erythrocytes. The direct test is applied to red cells which have been coated with antibody in vivo (e.g., in hemolytic disease of newborn, autoimmune hemolytic anemia, and transfusion reactions). The indirect test is applied to serum to detect the presence of antibody (e.g., in detection of incompatibility in cross-matching tests, detection and identification of irregular antibodies, and in detection of antibodies not identifiable by other means).
  • Corrosion Casting [M0024939]
    A tissue preparation technique that involves the injecting of plastic (acrylates) into blood vessels or other hollow viscera and treating the tissue with a caustic substance. This results in a negative copy or a solid replica of the enclosed space of the tissue that is ready for viewing under a scanning electron microscope.
  • Countercurrent Distribution [M0005262]
    A method of separation of two or more substances by repeated distribution between two immiscible liquid phases that move past each other in opposite directions. It is a form of liquid-liquid chromatography. (Stedman, 25th ed)
  • Counterimmunoelectrophoresis [M0005263]
    Immunoelectrophoresis in which immunoprecipitation occurs when antigen at the cathode is caused to migrate in an electric field through a suitable medium of diffusion against a stream of antibody migrating from the anode as a result of endosmotic flow.
  • Cross Circulation [M0005341]
    The circulation in a portion of the body of one individual of blood supplied from another individual.
  • Crosses, Genetic [M0005350]
  • Crossmatching, Blood [M0002700]
  • Cryoelectron Microscopy [M0029934]
    Electron microscopy involving rapid freezing of the samples. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.
  • Cryonic Suspension [M0024370]
  • Cryopreservation [M0024369]
    Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.
  • Cryoultramicrotomy [M0025334]
    The technique of using a cryostat or freezing microtome, in which the temperature is regulated to -20 degrees Celsius, to cut ultrathin frozen sections for microscopic (usually, electron microscopic) examination.
  • Crystallography [M0005404]
    The branch of science that deals with the geometric description of crystals and their internal arrangement. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Crystallography, X-Ray [M0027591]
    The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Culture Techniques [M0454589]
    Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or EMBRYO in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.
  • Cytodiagnosis [M0005599]
    Diagnosis of the type and, when feasible, the cause of a pathologic process by means of microscopic study of cells in an exudate or other form of body fluid. (Stedman, 26th ed)
  • Cytological Techniques [M0005602]
  • Cytophotometry [M0005611]
    A method for the study of certain organic compounds within cells, in situ, by measuring the light intensities of the selectively stained areas of cytoplasm. The compounds studied and their locations in the cells are made to fluoresce and are observed under a microscope.
  • Cytotoxicity Tests, Immunologic [M0005626]
    The demonstration of the cytotoxic effect on a target cell of a lymphocyte, a mediator released by a sensitized lymphocyte, an antibody, or complement.
  • DC Polarography [M0424609]
    A type of polarography in which the voltage is applied in a linear sweep fashion.
  • Decalcification Technique [M0005711]
  • Densitometry [M0005837]
  • Densitometry, X-Ray [M0005838]
    Measurement of the degree of darkening of X-ray film by means of a photocell which measures light transmission through the film.
  • Dental Soldering [M0020138]
    The joining of pieces of metal through the use of an alloy which has a lower melting point, usually at least 100 degrees Celsius below the fusion temperature of the parts being soldered. In dentistry, soldering is used for joining components of a dental appliance, as in assembling a bridge, joining metals to orthodontic bands, or adding to the bulk of certain structures, such as the establishment of proper contact areas on inlays and crowns with adjacent teeth. (Illustrated Dictionary of Dentistry, 1982)
  • Dermatoglyphics [M0006054]
    The study of the patterns of ridges of the skin of the fingers, palms, toes, and soles.
  • determination [M0030240]
  • Deuterium Exchange Measurement [M0439734]
    A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.
  • Differential Thermal Analysis [M0006359]
    Technique by which phase transitions of chemical reactions can be followed by observation of the heat absorbed or liberated.
  • Dilution Technics [M0011224]
  • Disk Diffusion Antimicrobial Tests [M0490513]
    A method where a culturing surface inoculated with microbe is exposed to small disks containing known amounts of a chemical agent resulting in a zone of inhibition (usually in millimeters) of growth of the microbe corresponding to the susceptibility of the strain to the agent.
  • Dissection [M0006586]
    The separation and isolation of tissues for surgical purposes, or for the analysis or study of their structures.
  • DNA Mutational Analysis [M0006656]
    Biochemical identification of mutational changes in a nucleotide sequence.
  • Dot Immunoblotting [M0023291]
  • Drug Screening Assays, Antitumor [M0006844]
    Methods of investigating the effectiveness of anticancer cytotoxic drugs and biologic inhibitors. These include in vitro cell-kill models and cytostatic dye exclusion tests as well as in vivo measurement of tumor growth parameters in laboratory animals.
  • Duke Method [M0002652]
  • Dye Dilution Technique [M0006902]
    Method for assessing flow through a system by injection of a known quantity of dye into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)
  • Dye Exclusion Assays, Antitumor [M0006845]
  • Electric Stimulation [M0007169]
    Use of electric potential or currents to elicit biological responses.
  • Electron Diffraction Microscopy [M0410030]
  • Electron Probe Microanalysis [M0007193]
    Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.
  • Electron Spin Resonance Spectroscopy [M0007195]
    A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.
  • Electrophoresis [M0007208]
    An electrochemical process in which macromolecules or colloidal particles with a net electric charge migrate in a solution under the influence of an electric current.
  • Electrophoresis, Agar Gel [M0007210]
    Electrophoresis in which agar or agarose gel is used as the diffusion medium.
  • Electrophoresis, Capillary [M0028475]
    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)
  • Electrophoresis, Cellulose Acetate [M0007211]
    Electrophoresis in which cellulose acetate is the diffusion medium.
  • Electrophoresis, Disc [M0007212]
    Electrophoresis in which discontinuities in both the voltage and pH gradients are introduced by using buffers of different composition and pH in the different parts of the gel column. The term 'disc' was originally used as an abbreviation for 'discontinuous' referring to the buffers employed, and does not have anything to do with the shape of the separated zones.
  • Electrophoresis, Gel, Pulsed-Field [M0025216]
    Electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.
  • Electrophoresis, Gel, Two-Dimensional [M0023331]
    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.
  • Electrophoresis, Microchip [M0453448]
    A highly miniaturized version of ELECTROPHORESIS performed in a microfluidic device.
  • Electrophoresis, Paper [M0007213]
    Electrophoresis in which paper is used as the diffusion medium. This technique is confined almost entirely to separations of small molecules such as amino acids, peptides, and nucleotides, and relatively high voltages are nearly always used.
  • Electrophoresis, Polyacrylamide Gel [M0007214]
    Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
  • Electrophoresis, Starch Gel [M0007216]
    Electrophoresis in which a starch gel (a mixture of amylose and amylopectin) is used as the diffusion medium.
  • Electrophoretic Mobility Shift Assay [M0369618]
    An electrophoretic technique for assaying the binding of one compound to another. Typically one compound is labeled to follow its mobility during electrophoresis. If the labeled compound is bound by the other compound, then the mobility of the labeled compound through the electrophoretic medium will be retarded.
  • Electroporation [M0027505]
    A technique in which electric pulses of intensity in kilovolts per centimeter and of microsecond-to-millisecond duration cause a temporary loss of the semipermeability of CELL MEMBRANES, thus leading to ion leakage, escape of metabolites, and increased uptake by cells of drugs, molecular probes, and DNA.
  • Embryo Culture Techniques [M0452903]
    The technique of maintaining or growing mammalian EMBRYOS in vitro. This method offers an opportunity to observe EMBRYONIC DEVELOPMENT; METABOLISM; and susceptibility to TERATOGENS
  • EMIT [M0373291]
  • Enzyme Immunoassay [M0011100]
  • Enzyme Multiplied Immunoassay Technique [M0026171]
    An immunoenzyme test for the presence of drugs and other substances in urine and blood. The test uses enzyme linked antibodies that react only with the particular drug for which the sample is being tested.
  • Enzyme Tests [M0007525]
  • Enzyme-Labeled Antibody Technique [M0011097]
  • Enzyme-Linked Immunosorbent Assay [M0007526]
    An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
  • Epitope Mapping [M0027884]
    Methods used for studying the interactions of antibodies with specific regions of protein antigens. Important applications of epitope mapping are found within the area of immunochemistry.
  • Erythrocyte Aggregation [M0007693]
    The formation of clumps of RED BLOOD CELLS under low or non-flow conditions, resulting from the attraction forces between the red blood cells. The cells adhere to each other in rouleaux aggregates. Slight mechanical force, such as occurs in the circulation, is enough to disperse these aggregates. Stronger or weaker than normal aggregation may result from a variety of effects in the ERYTHROCYTE MEMBRANE or in BLOOD PLASMA. The degree of aggregation is affected by ERYTHROCYTE DEFORMABILITY, erythrocyte membrane sialylation, masking of negative surface charge by plasma proteins, etc. BLOOD VISCOSITY and the ERYTHROCYTE SEDIMENTATION RATE are affected by the amount of erythrocyte aggregation and are parameters used to measure the aggregation.
  • Erythrocyte Size Determination [M0007704]
  • Estrus Detection [M0007800]
    Methods for recognizing the state of ESTRUS.
  • FIGLU Test [M0008464]
    A urine test for formiminoglutamic acid, an intermediate metabolite in L-histidine catabolism in the conversion of L-histidine to L-glutamic acid. It may be an indicator of vitamin B12 or folic acid deficiency or liver disease.
  • Film Dosimetry [M0008478]
    Use of a device (film badge) for measuring exposure of individuals to radiation. It is usually made of metal, plastic, or paper and loaded with one or more pieces of x-ray film.
  • Filtration [M0008479]
    A process of separating particulate matter from a fluid, such as air or a liquid, by passing the fluid carrier through a medium that will not pass the particulates. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Fingerprints, Nucleotide [M0015073]
  • Fingerprints, Peptide [M0016228]
  • Flame Ionization [M0008535]
    Pyrolysis of organic compounds at the temperature of a hydrogen-air flame to produce ionic intermediates which can be collected and the resulting ion current measured by gas chromatography.
  • Flocculation Tests [M0008562]
    Precipitin tests in which precipitation occurs over a narrow range of antigen-antibody ratio, due chiefly to peculiarities of the antibody (precipitin). (From Stedman, 26th ed)
  • Flow Cytometry [M0008573]
    Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
  • Flow Injection Analysis [M0025863]
    The analysis of a chemical substance by inserting a sample into a carrier stream of reagent using a sample injection valve that propels the sample downstream where mixing occurs in a coiled tube, then passes into a flow-through detector and a recorder or other data handling device.
  • Flowmetry [M0019007]
  • Fluorescence Polarization [M0008604]
    Measurement of the polarization of fluorescent light from solutions or microscopic specimens. It is used to provide information concerning molecular size, shape, and conformation, molecular anisotropy, electronic energy transfer, molecular interaction, including dye and coenzyme binding, and the antigen-antibody reaction.
  • Fluorescence Polarization Immunoassay [M0024787]
    Fluoroimmunoassay where detection of the hapten-antibody reaction is based on measurement of the increased polarization of fluorescence-labeled hapten when it is combined with antibody. The assay is very useful for the measurement of small haptenic antigens such as drugs at low concentrations.
  • Fluorescence Recovery After Photobleaching [M0410438]
    A method used to study the lateral movement of MEMBRANE PROTEINS and LIPIDS. A small area of a cell membrane is bleached by laser light and the amount of time necessary for unbleached fluorescent marker-tagged proteins to diffuse back into the bleached site is a measurement of the cell membrane's fluidity. The diffusion coefficient of a protein or lipid in the membrane can be calculated from the data. (From Segen, Current Med Talk, 1995).
  • Fluorescence Resonance Energy Transfer [M0398309]
    A type of FLUORESCENCE SPECTROSCOPY using two FLUORESCENT DYES with overlapping emission and absorption spectra, which is used to indicate proximity of labeled molecules. This technique is useful for studying interactions of molecules and PROTEIN FOLDING.
  • Fluorescence Spectrophotometry [M0020230]
  • Fluorescence Spectroscopy [M0020231]
  • Fluorescence-Activated Cell Sorting [M0008574]
  • Fluorescent Antibody Technique [M0008606]
    Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
  • Fluorescent Antibody Technique, Direct [M0028487]
    A form of fluorescent antibody technique utilizing a fluorochrome conjugated to an antibody, which is added directly to a tissue or cell suspension for the detection of a specific antigen. (Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
  • Fluorescent Antibody Technique, Indirect [M0028485]
    A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
  • Fluorescent Protein Tracing [M0008607]
  • Fluorescent Treponemal Antibody-Absorption Test [M0025201]
    Serologic assay that detects antibodies to Treponema pallidum, the etiologic agent of syphilis. After diluting the patient's serum to remove non-specific antibodies, the serum is mixed on a glass slide with Nichol's strain of Treponema pallidum. An antigen-antibody reaction occurs if the test is positive and the bound antibodies are detected with fluoresceinated antihuman gamma-globulin antibody.
  • Fluoroimmunoassay [M0023355]
    The use of fluorescence spectrometry to obtain quantitative results for the FLUORESCENT ANTIBODY TECHNIQUE. One advantage over the other methods (e.g., radioimmunoassay) is its extreme sensitivity, with a detection limit on the order of tenths of microgram/liter.
  • Fluorometry [M0008629]
  • Food Analysis [M0008673]
  • Fractional Precipitation [M0008799]
  • Fractionation, Field Flow [M0398273]
    Separation of molecules and particles by a simultaneous action of carrier liquid flow and focusing field forces (electrical, sedimentation, or thermal), without a stationary phase.
  • Freeze Drying [M0008834]
    Method of tissue preparation in which the tissue specimen is frozen and then dehydrated at low temperature in a high vacuum. This method is also used for dehydrating pharmaceutical and food products.
  • Freeze Fracturing [M0008836]
    Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.
  • Fungal Count [M0023314]
  • Fungus Drug Sensitivity Tests [M0359493]
  • Gas Chromatography-Mass Spectrometry [M0013077]
    A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
  • Gel Shift Analysis [M0369619]
  • Gene Expression Profiling [M0328024]
    The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
  • Genetic Complementation Test [M0009122]
    A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
  • Hardness Tests [M0009803]
  • Helminth Drug Sensitivity Tests [M0359491]
  • Hemadsorption Inhibition Tests [M0010021]
  • Hemagglutination Inhibition Tests [M0010023]
    Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of hemagglutination.
  • Hemagglutination Tests [M0010024]
    Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)
  • Hematologic Tests [M0010045]
    Tests used in the analysis of the hemic system.
  • Hemoglobinometry [M0010128]
    Measurement of hemoglobin concentration in blood.
  • Hemolytic Plaque Technique [M0010144]
  • Heterozygote Detection [M0010304]
    Identification of genetic carriers for a given trait.
  • Histocompatibility Testing [M0010412]
    Identification of the major histocompatibility antigens of transplant DONORS and potential recipients, usually by serological tests. Donor and recipient pairs should be of identical ABO blood group, and in addition should be matched as closely as possible for HISTOCOMPATIBILITY ANTIGENS in order to minimize the likelihood of allograft rejection. (King, Dictionary of Genetics, 4th ed)
  • Histocytochemistry [M0010416]
    Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.
  • Histocytological Preparation Techniques [M0025306]
    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.
  • Histological Labeling [M0355510]
  • Histological Techniques [M0010417]
  • HLA Typing [M0010413]
  • Illicit Drug Detection [M0024214]
  • Illicit Drug Testing [M0024215]
  • Image Cytometry [M0028433]
    A technique encompassing morphometry, densitometry, neural networks, and expert systems that has numerous clinical and research applications and is particularly useful in anatomic pathology for the study of malignant lesions. The most common current application of image cytometry is for DNA analysis, followed by quantitation of immunohistochemical staining.
  • Imaging, Chemical Shift [M0015035]
  • Immune Adherence Reaction [M0011065]
    A method for the detection of very small quantities of antibody in which the antigen-antibody-complement complex adheres to indicator cells, usually primate erythrocytes or nonprimate blood platelets. The reaction is dependent on the number of bound C3 molecules on the C3b receptor sites of the indicator cell.
  • Immunoassay [M0011088]
    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.
  • Immunoblotting [M0023293]
    Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
  • Immunoblotting, Reverse [M0023294]
  • Immunocytochemistry [M0011151]
  • Immunodiagnosis [M0011162]
  • Immunodiffusion [M0009051]
    Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.
  • Immunoelectroblotting [M0023292]
  • Immunoelectrophoresis [M0011092]
    A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.
  • Immunoelectrophoresis, Two-Dimensional [M0011093]
    Immunoelectrophoresis in which a second electrophoretic transport is performed on the initially separated antigen fragments into an antibody-containing medium in a direction perpendicular to the first electrophoresis.
  • Immunoenzyme Techniques [M0011094]
    Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
  • Immunofluorescence Microscopy [M0013813]
  • Immunogold Techniques [M0011148]
  • Immunogold-Silver Techniques [M0011149]
  • Immunohistochemistry [M0011146]
    Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
  • Immunohistocytochemistry [M0011147]
  • Immunolabeling Techniques [M0011150]
  • Immunologic Techniques [M0011161]
  • Immunologic Tests [M0011163]
    Diagnostic techniques involving the demonstration or measurement of an immune response, including antibody production or assay, antigen-antibody reactions, serologic cross-reactivity, delayed hypersensitivity reactions, or heterogenetic responses.
  • Immunomagnetic Separation [M0027418]
    A 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 (BONE MARROW PURGING) of patients who are to undergo autologous bone marrow transplantation.
  • Immunoperoxidase Techniques [M0011095]
  • Immunophenotyping [M0024630]
    Process of classifying cells of the immune system based on structural and functional differences. The process is commonly used to analyze and sort T-lymphocytes into subsets based on CD antigens by the technique of flow cytometry.
  • Immunoprecipitation [M0017452]
    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.
  • Immunoradiometric Assay [M0023936]
    Form of radioimmunoassay in which excess specific labeled antibody is added directly to the test antigen being measured.
  • Immunosorbent Techniques [M0011168]
    Techniques for removal by adsorption and subsequent elution of a specific antibody or antigen using an immunosorbent containing the homologous antigen or antibody.
  • In Situ Hybridization [M0026417]
    A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
  • In Situ Hybridization, Fluorescence [M0026418]
    A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.
  • Indicator Dilution Techniques [M0011223]
    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)
  • Inductively Coupled Plasma Atomic Emission Spectrophotomety [M0448219]
  • Interferometry [M0011487]
    Measurement of distances or movements by means of the phenomena caused by the interference of two rays of light (optical interferometry) or of sound (acoustic interferometry).
  • Inverse PCR [M0024636]
  • Isoelectric Focusing [M0011756]
    Electrophoresis in which a pH gradient is established in a gel medium and proteins migrate until they reach the site (or focus) at which the pH is equal to their isoelectric point.
  • isolation [M0030501]
  • isolation & purification [M0030500]
    Used with bacteria, viruses, fungi, protozoa, and helminths for the obtaining of pure strains or for the demonstration of the presence of or identification of organisms by DNA analyses, immunologic, or other methods, including culture techniques. It is used also with biological substances and chemicals for the isolation and purification of the constituents.
  • Isotachophoresis [M0007209]
  • Ivy Method [M0002653]
  • Karyometry [M0011930]
  • Karyotyping [M0011931]
    Mapping of the full chromosome set of the nucleus of a cell. The chromosome characteristics of an individual or a cell line are usually presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere. (From Stedman, 25th ed)
  • Kidney Function Tests [M0012017]
  • Kirby-Bauer Disk-Diffusion Method [M0490514]
  • Laboratory Procedures [M0006179]
  • Laboratory Techniques and Procedures [M0006180]
    Methods, procedures, and tests performed in the laboratory with an intended application to the diagnosis of disease or understanding of physiological functioning. The techniques include examination of microbiological, cytological, chemical, and biochemical specimens, normal and pathological.
  • Lactose Tolerance Test [M0012183]
  • Laser Microscopy [M0027897]
  • Laser Scanning Cytometry [M0457948]
    A scanning microscope-based, cytofluorimetry technique for making fluorescence measurements and topographic analysis on individual cells. Lasers are used to excite fluorochromes in labeled cellular specimens. Fluorescence is detected in multiple discrete wavelengths and the locational data is processed to quantitatively assess APOPTOSIS; PLOIDIES; cell proliferation; GENE EXPRESSION; PROTEIN TRANSPORT; and other cellular processes.
  • Laser Scanning Microscopy [M0027898]
  • Latex Fixation Tests [M0012255]
    Passive agglutination tests in which antigen is adsorbed onto latex particles which then clump in the presence of antibody specific for the adsorbed antigen. (From Stedman, 26th ed)
  • Leukocyte Adherence Inhibition Test [M0012404]
    Test for cell-mediated antitumor immunity and related serum blocking factors based on the finding that leukocytes from cancer patients, but not from controls, when mixed in vitro with antigenic extracts of tumors of the same histological type, undergo a diminution in their normal adherence to glass surfaces. Sera from tumor-bearing patients block the LAI reaction of their own leukocytes or those of other patients with the same type of tumor.
  • Leukocyte Count, Differential [M0012406]
  • Leukocyte Migration Test [M0003763]
  • Limulus Test [M0012520]
    Sensitive method for detection of bacterial endotoxins and endotoxin-like substances that depends on the in vitro gelation of Limulus amebocyte lysate (LAL), prepared from the circulating blood (amebocytes) of the horseshoe crab, by the endotoxin or related compound. Used for detection of endotoxin in body fluids and parenteral pharmaceuticals.
  • Liver Function Tests [M0012650]
  • Luminescent Measurements [M0464536]
    Techniques using light resulting from PHYSICAL LUMINESCENCE emitted by LUMINESCENT PROTEINS and LUMINESCENT AGENTS.
  • Lymphocyte Activation [M0012805]
    Morphologic alteration of small lymphocytes in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific antigens. It may also occur in vivo, as in GRAFT REJECTION and chronic myelogenous leukemia (LEUKEMIA, MYELOID, CHRONIC).
  • Lymphocyte Culture Test, Mixed [M0012408]
    Measure of histocompatibility at the HL-A locus. Peripheral blood lymphocytes from two individuals are mixed together in tissue culture for several days. Lymphocytes from incompatible individuals will stimulate each other to proliferate significantly (measured by tritiated thymidine uptake) whereas those from compatible individuals will not. In the one-way MLC test, the lymphocytes from one of the individuals are inactivated (usually by treatment with MITOMYCIN or radiation) thereby allowing only the untreated remaining population of cells to proliferate in response to foreign histocompatibility antigens.
  • Lymphocyte Immunophenotyping [M0024631]
  • Lymphocyte Subtyping [M0024632]
  • Lymphocytotoxicity Tests, Antiglobulin-Augmented [M0005628]
  • Macrophage Migration Test [M0003764]
  • Manometry [M0013008]
    Measurement of the pressure or tension of liquids or gases with a manometer.
  • Mass Spectrometry [M0020241]
    An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
  • Microarray Analysis of Gene Expression [M0351377]
  • Microbial Inactivation [M0473809]
  • Microbial Sensitivity Tests [M0013763]
    Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).
  • Microbiological Techniques [M0013766]
    Techniques used in microbiology.
  • Microchip Analytical Procedures [M0453442]
    The preparation and analysis of samples on miniaturized devices.
  • Microcytotoxicity Test [M0005629]
  • Microfluidic Analytical Techniques [M0453447]
    Methods utilizing the principles of MICROFLUIDICS for sample handling, reagent mixing, and separation and detection of specific components in fluids.
  • Micromanipulation [M0013788]
    The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.
  • Micronucleus Tests [M0023303]
    Induction and quantitative measurement of chromosomal damage leading to the formation of micronuclei (MICRONUCLEI, CHROMOSOME-DEFECTIVE) in cells which have been exposed to genotoxic agents or IONIZING RADIATION.
  • Microscopy [M0013808]
    The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.
  • Microscopy, Atomic Force [M0027912]
    A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.
  • Microscopy, Confocal [M0027896]
    A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
  • Microscopy, Confocal, Laser Scanning [M0027895]
  • Microscopy, Differential Interference Contrast [M0405882]
  • Microscopy, Electron [M0013809]
    Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
  • Microscopy, Electron, Scanning [M0013811]
    Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
  • Microscopy, Electron, Scanning Transmission [M0026341]
    A type of TRANSMISSION ELECTRON MICROSCOPY in which the object is examined directly by an extremely narrow electron beam scanning the specimen point-by-point and using the reactions of the electrons that are transmitted through the specimen to create the image. It should not be confused with SCANNING ELECTRON MICROSCOPY.
  • Microscopy, Electron, Transmission [M0013810]
    Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
  • Microscopy, Energy-Filtering Transmission Electron [M0452473]
    An analytical transmission electron microscopy method using an electron microscope fitted with an energy filtering lens. The method is based on the principle that some of the ELECTRONS passing through the specimen will lose energy when they ionize inner shell electrons of the atoms in the specimen. The amount of energy loss is dependent upon the element. Analysis of the energy loss spectrum (ELECTRON ENERGY-LOSS SPECTROSCOPY) reveals the elemental composition of a specimen. It is used analytically and quantitatively to determine which, how much of, and where specific ELEMENTS are in a sample. For example, it is used for elemental mapping of PHOSPHORUS to trace the strands of NUCLEIC ACIDS in nucleoprotein complexes.
  • Microscopy, Fluorescence [M0013812]
    Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
  • Microscopy, Fluorescence, Multiphoton [M0410252]
    Fluorescence microscopy utilizing multiple low-energy photons to produce the excitation event of the fluorophore. Multiphoton microscopes have a simplified optical path in the emission side due to the lack of an emission pinhole, which is necessary with normal confocal microscopes. Ultimately this allows spatial isolation of the excitation event, enabling deeper imaging into optically thick tissue, while restricting photobleaching and phototoxicity to the area being imaged.
  • Microscopy, Interference [M0013814]
    The science and application of a double-beam transmission interference microscope in which the illuminating light beam is split into two paths. One beam passes through the specimen while the other beam reflects off a reference mirror before joining and interfering with the other. The observed optical path difference between the two beams can be measured and used to discriminate minute differences in thickness and refraction of non-stained transparent specimens, such as living cells in culture.
  • Microscopy, Interference Reflection [M0405126]
  • Microscopy, Phase-Contrast [M0013815]
    A form of interference microscopy in which variations of the refracting index in the object are converted into variations of intensity in the image. This is achieved by the action of a phase plate.
  • Microscopy, Polarization [M0013816]
    Microscopy using polarized light in which phenomena due to the preferential orientation of optical properties with respect to the vibration plane of the polarized light are made visible and correlated parameters are made measurable.
  • Microscopy, Scanning Probe [M0027913]
    Scanning microscopy in which a very sharp probe is employed in close proximity to a surface, exploiting a particular surface-related property. When this property is local topography, the method is atomic force microscopy (MICROSCOPY, ATOMIC FORCE), and when it is local conductivity, the method is scanning tunneling microscopy (MICROSCOPY, SCANNING TUNNELING).
  • Microscopy, Scanning Tunneling [M0024822]
    A type of scanning probe microscopy in which a very sharp conducting needle is swept just a few angstroms above the surface of a sample. The tiny tunneling current that flows between the sample and the needle tip is measured, and from this are produced three-dimensional topographs. Due to the poor electron conductivity of most biological samples, thin metal coatings are deposited on the sample.
  • Microscopy, Ultraviolet [M0013817]
    Microscopy in which the image is formed by ultraviolet radiation and is displayed and recorded by means of photographic film.
  • Microscopy, Video [M0028041]
    Microscopy in which television cameras are used to brighten magnified images that are otherwise too dark to be seen with the naked eye. It is used frequently in TELEPATHOLOGY.
  • Microtomy [M0013827]
    The technique of using a microtome to cut thin or ultrathin sections of tissues embedded in a supporting substance. The microtome is an instrument that hold a steel, glass or diamond knife in clamps at an angle to the blocks of prepared tissues, which it cuts in sections of equal thickness.
  • Migration Inhibitory Tests, Leukocyte [M0003762]
  • Minimum Inhibitory Concentration [M0013764]
  • Moire Topography [M0024337]
    A method of three-dimensional morphometry in which contour maps are produced from the overlapping interference fringes created when an object is illuminated by beams of coherent light issuing from two different point sources.
  • Molecular Probe Techniques [M0023610]
    The use of devices which use detector molecules to detect, investigate, or analyze other molecules, macromolecules, molecular aggregates, or organisms.
  • mRNA Differential Display [M0352576]
    Analysis of differentially expressed RNA transcripts from different tissues, cells, strains, or conditions.
  • Mutagenicity Tests [M0014272]
    Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.
  • Mycological Typing Techniques [M0025233]
    Procedures for identifying types and strains of fungi.
  • Negative Staining [M0025341]
    The technique of washing tissue specimens with a concentrated solution of a heavy metal salt and letting it dry. The specimen will be covered with a very thin layer of the metal salt, being excluded in areas where an adsorbed macromolecule is present. The macromolecules allow electrons from the beam of an electron microscope to pass much more readily than the heavy metal; thus, a reversed or negative image of the molecule is created.
  • Nephelometry [M0014622]
  • Nephelometry and Turbidimetry [M0014623]
    Chemical analysis based on the phenomenon whereby light, passing through a medium with dispersed particles of a different refractive index from that of the medium, is attenuated in intensity by scattering. In turbidimetry, the intensity of light transmitted through the medium, the unscattered light, is measured. In nephelometry, the intensity of the scattered light is measured, usually, but not necessarily, at right angles to the incident light beam.
  • Neutralization Tests [M0014779]
    Titration of an antiserum by testing a series of dilutions of virus or immune serum to a given end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).
  • Neutron Activation Analysis [M0014780]
    Activation analysis in which the specimen is bombarded with neutrons. Identification is made by measuring the resulting radioisotopes. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Neutron Diffraction [M0402384]
    The scattering of NEUTRONS by matter, especially crystals, with accompanying variation in intensity due to interference effects. It is useful in CRYSTALLOGRAPHY and POWDER DIFFRACTION.
  • Nucleotide Mapping [M0015074]
    Two-dimensional separation and analysis of nucleotides.
  • Optical Rotatory Dispersion [M0015364]
    The method of measuring the dispersion of an optically active molecule to determine the relative magnitude of right- or left-handed components and sometimes structural features of the molecule.
  • Organ Culture Techniques [M0015390]
    A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)
  • Pancreatic Function Tests [M0015799]
    Tests based on the biochemistry and physiology of the exocrine pancreas and involving analysis of blood, duodenal contents, feces, or urine for products of pancreatic secretion.
  • Paraffin Embedding [M0025331]
    The infiltrating of tissue specimens with paraffin, as a supporting substance, to prepare for sectioning with a microtome.
  • Parasite Egg Count [M0015917]
  • Parasitic Sensitivity Tests [M0352393]
    Tests that demonstrate the relative effectiveness of chemotherapeutic agents against specific parasites.
  • Passive Cutaneous Anaphylaxis [M0015998]
    An evanescent cutaneous reaction occurring when antibody is injected into a local area on the skin and antigen is subsequently injected intravenously along with a dye. The dye makes the rapidly occurring capillary dilatation and increased vascular permeability readily visible by leakage into the reaction site. PCA is a sensitive reaction for detecting very small quantities of antibodies and is also a method for studying the mechanisms of immediate hypersensitivity.
  • Peptide Mapping [M0016229]
    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.
  • Periodic Acid-Schiff Reaction [M0016316]
    A histochemical technique for staining carbohydrates. It is based on PERIODIC ACID oxidation of a substance containing adjacent hydroxyl groups. The resulting aldehydes react with Schiff reagent to form a colored product.
  • Peroxidase-Antiperoxidase Complex Technique [M0011098]
  • Peroxidase-Labeled Antibody Technique [M0011099]
  • Phosphorescent Measurements [M0464540]
  • Photometry [M0016751]
  • Photomicrography [M0016752]
    Photography of objects viewed under a microscope using ordinary photographic methods.
  • Pituitary Function Tests [M0016909]
  • Pituitary-Adrenal Function Tests [M0016923]
  • Plaque Assay [M0016975]
    Method for measuring viral infectivity and multiplication in cultured cells. Clear lysed areas or plaques develop as the viral particles are released from the infected cells during incubation. With some viruses, the cells are killed by a cytopathic effect; with others, the infected cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque cells contain viral antigens which can be measured by immunofluorescence.
  • Plastic Embedding [M0025332]
    The infiltrating of histological specimens with plastics, including acrylic resins, epoxy resins and polyethylene glycol, for support of the tissues in preparation for sectioning with a microtome.
  • Platelet Function Tests [M0017020]
  • Polarography [M0017107]
    An electrochemical technique for measuring the current that flows in solution as a function of an applied voltage. The observed polarographic wave, resulting from the electrochemical response, depends on the way voltage is applied (linear sweep or differential pulse) and the type of electrode used. Usually a mercury drop electrode is used.
  • Potentiometry [M0017388]
    Solution titration in which the end point is read from the electrode-potential variations with the concentrations of potential determining ions. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Pour Plate Count [M0023315]
  • Powder Diffraction [M0402383]
    Method of using a polycrystalline powder and Rietveld refinement (LEAST SQUARES ANALYSIS) of X-RAY DIFFRACTION or NEUTRON DIFFRACTION. It circumvents the difficulties of producing single large crystals.
  • Precipitin Tests [M0017453]
    Serologic tests in which a positive reaction manifested by visible precipitation occurs when a soluble ANTIGEN reacts with its ANTIBODIES.
  • Preservation, Biological [M0017561]
  • Primary Cell Culture [M0452904]
  • Protein Engineering [M0023358]
    Procedures by which protein structure and function are changed or created in vitro by altering existing or synthesizing new structural genes that direct the synthesis of proteins with sought-after properties. Such procedures may include the design of MOLECULAR MODELS of proteins using COMPUTER GRAPHICS or other molecular modeling techniques; site-specific mutagenesis (MUTAGENESIS, SITE-SPECIFIC) of existing genes; and DIRECTED MOLECULAR EVOLUTION techniques to create new genes.
  • Protein-Bound Iodine Test [M0021479]
  • Proton Induced X Ray Emission Spectrometry [M0455691]
  • Protozoal Drug Sensitivity Tests [M0359490]
  • Prussian Blue Reaction [M0017938]
    The reaction of potassium ferrocyanide with ferric iron to yield a dark blue precipitate at the sites of the ferric iron. Used to determine ferric iron in tissues, particularly in the diagnosis of disorders of iron metabolism.
  • Pulse Polarography [M0424610]
    A type of polarography in which the voltage is applied in a differential pulse fashion.
  • Pulse Radiolysis [M0018155]
    Use of a pulse of X-rays or fast electrons to generate free radicals for spectroscopic examination.
  • purification [M0030502]
  • Quick Test [M0017907]
  • Radiation Monitoring [M0018384]
    The observation, either continuously or at intervals, of the levels of radiation in a given area, generally for the purpose of assuring that they have not exceeded prescribed amounts or, in case of radiation already present in the area, assuring that the levels have returned to those meeting acceptable safety standards.
  • Radioallergosorbent Test [M0018407]
    An in vitro allergen radioimmunoassay in which allergens are coupled to an immunosorbent. The coupled allergens bind the IgE in the sera of patients which in turn binds radioisotope-labeled anti-IMMUNOGLOBULIN E antibodies.
  • Radioimmunoassay [M0018419]
    Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.
  • Radioimmunoprecipitation Assay [M0023895]
    Sensitive assay using radiolabeled ANTIGENS to detect specific ANTIBODIES in SERUM. The antigens are allowed to react with the serum and then precipitated using a special reagent such as PROTEIN A sepharose beads. The bound radiolabeled immunoprecipitate is then commonly analyzed by gel electrophoresis. Radioimmunoprecipitation assay (RIPA) is often used as a confirmatory test for diagnosing the presence of HIV ANTIBODIES.
  • Radioimmunosorbent Test [M0018420]
    Radioimmunoassay of proteins using antibody coupled to an immunosorbent.
  • Radioisotope Dilution Technique [M0018421]
    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)
  • Radioligand Assay [M0018426]
    Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).
  • Radiometry [M0018436]
    The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.
  • Raman Optical Activity Spectroscopy [M0444999]
    A plot of the difference in intensities between Raman scattered light using right and left circularly polarized incident light (CIRCULAR DICHROISM).
  • Random Amplified Polymorphic DNA Technique [M0028511]
    Technique that utilizes low-stringency polymerase chain reaction (PCR) amplification with single primers of arbitrary sequence to generate strain-specific arrays of anonymous DNA fragments. RAPD technique may be used to determine taxonomic identity, assess kinship relationships, analyze mixed genome samples, and create specific probes.
  • Replica Techniques [M0025344]
    Methods of preparing tissue specimens for visualization using an electron microscope, usually a scanning electron microscope. The methods involve the creation of exact copies of the specimens by making a mold or cast (i.e., replica) of the specimen.
  • Research Subject Recruitment [M0027850]
  • Restriction Mapping [M0023338]
    Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.
  • Rinkel Serial Dilution Titration [M0024372]
  • Rosette Formation [M0019274]
    The in vitro formation of clusters consisting of a cell (usually a lymphocyte) surrounded by antigenic cells or antigen-bearing particles (usually erythrocytes, which may or may not be coated with antibody or antibody and complement). The rosette-forming cell may be an antibody-forming cell, a memory cell, a T-cell, a cell bearing surface cytophilic antibodies, or a monocyte possessing Fc receptors. Rosette formation can be used to identify specific populations of these cells.
  • Scintillation Counting [M0019529]
    Detection and counting of scintillations produced in a fluorescent material by ionizing radiation.
  • SDS-PAGE [M0007215]
  • Sedimentation Field Flow Fractionation [M0398274]
    Sedimentation field is either gravitational or centrifugal.
  • Sequence Analysis [M0026437]
    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.
  • Sequence Analysis, DNA [M0026438]
    A multistage process that includes DNA cloning, physical mapping, subcloning, sequencing, and information analysis.
  • Sequence Analysis, Protein [M0328074]
    A process that includes the determination of an amino acid sequence of a protein (or peptide, oligopeptide or peptide fragment) and the information analysis of the sequence.
  • Sequence Analysis, RNA [M0026439]
    A multistage process that includes RNA cloning, physical mapping, subcloning, sequencing, and information analysis.
  • Sequence Determination, Protein [M0331632]
  • Sequence Determinations [M0333395]
  • Sequence Determinations, DNA [M0333399]
  • Sequence Determinations, RNA [M0333402]
  • Sequencing By Hybridization [M0030066]
  • Serodiagnosis [M0019680]
  • Serologic Tests [M0019679]
    Diagnostic procedures involving immunoglobulin reactions.
  • Serotyping [M0019686]
  • Serum Bactericidal Test [M0023952]
    Method of measuring the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy. It is used to monitor the therapy in BACTERIAL ENDOCARDITIS; OSTEOMYELITIS and other serious bacterial infections. As commonly performed, the test is a variation of the broth dilution test. This test needs to be distinguished from testing of the naturally occurring BLOOD BACTERICIDAL ACTIVITY.
  • Sex Determination (Analysis) [M0019733]
    Validation of the SEX of an individual by inspection of the GONADS and/or by genetic tests.
  • Shadowing (Histology) [M0025342]
    The technique of spraying a tissue specimen with a thin coat of a heavy metal such as platinum. The specimen is sprayed from an oblique angle, which results in the uneven deposition of the coating. The varying thicknesses create a shadow effect and give a three-dimensional appearance to the specimen.
  • Silver Nitrate Staining [M0025337]
  • Silver Staining [M0025336]
    The use of silver, usually silver nitrate, as a reagent for producing contrast or coloration in tissue specimens.
  • Skin Window Technique [M0019945]
  • Solid Phase Extraction [M0488073]
    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.
  • Solid Phase Microextraction [M0488074]
    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.
  • Sound Spectrography [M0020181]
    The graphic registration of the frequency and intensity of sounds, such as speech, infant crying, and animal vocalizations.
  • Spectral Karyotyping [M0401303]
    The simultaneous identification of all chromosomes from a cell by fluorescence in situ hybridization (IN SITU HYBRIDIZATION, FLUORESCENCE) with chromosome-specific florescent probes that are discerned by their different emission spectra.
  • Spectrometry, Fluorescence [M0020229]
    Measurement of the intensity and quality of fluorescence.
  • Spectrometry, Gamma [M0020232]
    Determination of the energy distribution of gamma rays emitted by nuclei. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Spectrometry, Mass, Electrospray Ionization [M0352282]
    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, Secondary Ion [M0027922]
    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.
  • Spectrometry, X-Ray Emission [M0020233]
    The analysis of the spectrum of fluorescent X-RAYS, i.e. X-rays emitted after bombarding matter with high energy particles such as PROTONS; ELECTRONS; or higher energy X-rays. The identification and quantitation of ELEMENTS by this technique is based on the fact that the wavelength and intensity of the fluorescent X-rays are characteristic of specific elements and the concentration of the elements in the matter being analyzed.
  • Spectrophotometry [M0020236]
    The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
  • Spectrophotometry, Atomic [M0448217]
    Spectrophotometric techniques in which the samples are examined in the form of atoms based on their unique energy levels for ELECTRONS. They are used to analyze TRACE ELEMENTS, such as ALUMINUM; ARSENIC; BERYLLIUM; CALCIUM; COPPER; IRON; LEAD; and LITHIUM.
  • Spectrophotometry, Atomic Absorption [M0020237]
  • Spectrophotometry, Atomic Emission [M0448218]
  • Spectrophotometry, Infrared [M0020238]
    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)
  • Spectrophotometry, Ultraviolet [M0020239]
    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)
  • Spectroscopy, Electron Energy-Loss [M0452475]
    A technique for analysis of the chemical composition of molecules. A substance is bombarded with monochromatic ELECTRONS. Some of the electrons passing through the specimen will lose energy when they ionize inner shell electrons of the atoms in the specimen. The energy loss is element dependent. Analysis of the energy loss spectrum reveals the elemental composition of a specimen. ENERGY-FILTERED TRANSMISSION ELECTRON MICROSCOPY is a type of electron energy loss spectroscopy carried out in electron microscopes specially outfitted to analyze the spectrum of electron energy loss.
  • Spectroscopy, Mossbauer [M0023365]
    A spectroscopic technique which uses the Mossbauer effect (inelastic scattering of gamma radiation resulting from interaction with heavy nuclei) to monitor the small variations in the interaction between an atomic nucleus and its environment. Such variations may be induced by changes in temperature, pressure, chemical state, molecular conformation, molecular interaction, or physical site. It is particularly useful for studies of structure-activity relationship in metalloproteins, mobility of heavy metals, and the state of whole tissue and cell membranes.
  • Spectroscopy, Near-Infrared [M0028692]
    A noninvasive technique that uses the differential absorption properties of hemoglobin and myoglobin to evaluate tissue oxygenation and indirectly can measure regional hemodynamics and blood flow. Near-infrared light (NIR) can propagate through tissues and at particular wavelengths is differentially absorbed by oxygenated vs. deoxygenated forms of hemoglobin and myoglobin. Illumination of intact tissue with NIR allows qualitative assessment of changes in the tissue concentration of these molecules. The analysis is also used to determine body composition.
  • Spectrum Analysis [M0020240]
    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, 4th ed)
  • Spectrum Analysis, Raman [M0020242]
    Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light.
  • Sperm Count [M0020263]
    A count of SPERM in the ejaculum, expressed as number per milliliter.
  • Spin Trapping [M0028507]
    A technique for detecting short-lived reactive FREE RADICALS in biological systems by providing a nitrone or nitrose compound for an addition reaction to occur which produces an ELECTRON SPIN RESONANCE SPECTROSCOPY-detectable aminoxyl radical. In spin trapping, the compound trapping the radical is called the spin trap and the addition product of the radical is identified as the spin adduct. (Free Rad Res Comm 1990;9(3-6):163)
  • Spore Count [M0023316]
  • Spread Plate Count [M0023317]
  • Staining [M0355509]
    The use of a dye, reagent, or other material for producing coloration or contrast in biological materials for examination or observation.
  • Staining and Labeling [M0020410]
    The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.
  • Streak Plate Count [M0023318]
  • Street Drug Detection [M0024216]
  • Street Drug Testing [M0024217]
  • Subrenal Capsule Assay [M0020673]
    In vivo method of screening investigative anticancer drugs and biologic response modifiers for individual cancer patients. Fresh tumor tissue is implanted under the kidney capsule of immunocompetent mice or rats; gross and histological assessments follow several days after tumor treatment in situ.
  • Substance Abuse Detection [M0024218]
    Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.
  • Supercritical Fluid Extraction [M0376479]
  • Supershift Mobility Assay [M0369620]
  • Template Bleeding Time [M0002650]
  • Thermodilution [M0021300]
    Measurement of blood flow based on induction at one point of the circulation of a known change in the intravascular heat content of flowing blood and detection of the resultant change in temperature at a point downstream.
  • Thermogravimetry [M0021303]
    Technique whereby the weight of a sample can be followed over a period of time while its temperature is being changed (usually increased at a constant rate).
  • Thrombotest [M0017908]
  • Thyroid Function Tests [M0021480]
  • Time-Resolved Immunofluorometric Assay [M0023356]
  • Tissue Array Analysis [M0455901]
    The simultaneous analysis of multiple samples of TISSUES or CELLS from BIOPSY or in vitro culture that have been arranged in an array format on slides or microchips.
  • Tissue Culture Techniques [M0021577]
    A technique for maintaining or growing TISSUE in vitro, usually by DIFFUSION, perifusion, or PERFUSION. The tissue is cultured directly after removal from the host without being dispersed for cell culture.
  • Tissue Embedding [M0025330]
    The technique of placing cells or tissue in a supporting medium so that thin sections can be cut using a microtome. The medium can be paraffin wax (PARAFFIN EMBEDDING) or plastics (PLASTIC EMBEDDING) such as epoxy resins.
  • Tissue Fixation [M0025447]
    The technique of using FIXATIVES in the preparation of cytologic, histologic, or pathologic specimens for the purpose of maintaining the existing form and structure of all the constituent elements.
  • Titration [M0026089]
  • Titrimetry [M0026090]
    Chemical analysis by titration, the determination of a given component in solution by addition of a liquid reagent of known strength until a given endpoint (e.g., a change in color) is reached.
  • Tonometry [M0447383]
    Measurement of the pressure or tension of liquids or gases with a tonometer. It has been developed to measure pressure in the EYE; the BLOOD VESSELS; and the STOMACH.
  • Total Body Clearance Rate [M0013491]
  • Treponema Immobilization Test [M0021875]
    Syphilis serodiagnosis employing as the antigen Treponema pallidum obtained from rabbit syphilis orchitis. Treponemes are kept alive for a few hours in a special medium. When syphilitic serum and complement are added and incubated, the treponemes are immobilized, i.e., stop moving.
  • Tumor Stem Cell Assay [M0022151]
    A cytologic technique for measuring the functional capacity of tumor stem cells by assaying their activity. It is used primarily for the in vitro testing of antineoplastic agents.
  • Turbidimetry [M0014624]
  • Typing, Fungal [M0025235]
  • Ultracentrifugation [M0022231]
    Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • Ultramicrotomy [M0013828]
  • Urinalysis [M0025166]
    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.
  • Velocimetry [M0019008]
  • Virus Drug Sensitivity Tests [M0359492]
  • Virus Inactivation [M0415793]
    Inactivation of viruses by non-immune related techniques. They include extremes of pH, HEAT treatment, ultraviolet radiation, IONIZING RADIATION; DESICCATION; ANTISEPTICS; DISINFECTANTS; organic solvents, and DETERGENTS.
  • X-Ray Diffraction [M0023036]
    The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
  • X-Ray Emission Spectroscopy [M0020235]
  • Xenograft Model Antitumor Assays [M0360307]
    In vivo methods of screening investigative anticancer drugs, biologic response modifiers or radiotherapies. Human tumor tissue or cells are transplanted into mice or rats followed by tumor treatment regimens. A variety of outcomes are monitored to assess antitumor effectiveness.