assay /as·say/ (as´a) determination of the amount of a particular constituent of a mixture, or of the potency of a drug.
Assay
assay
assay [as´a]
biological assay bioassay.
CH50 assay a test of total complement activity as the capacity of serum to lyse a standard preparation of sheep red blood cells coated with antisheep erythrocyte antibody. The reciprocal of the dilution of serum that lyses 50 per cent of the erythrocytes is the whole complement titer in CH50 units per milliliter of serum.
enzyme-linked immunosorbent assay see ELISA.
microbiological assay assay by the use of microorganisms.
microcytotoxicity assay one using the pattern of lysis of peripheral blood lymphocytes in the presence of complement and typing sera to type serologically defined HLA antigens (HLA-A, -B, and -C antigens).
radioimmunoprecipitation assay (RIPA) immunoprecipitation conducted with radiolabeled antibody or antigen.
radioligand assay any assay procedure that uses radioisotopic labeling and biologically specific binding of reagents.
stem cell assay a measurement of the potency of antineoplastic drugs, based on their ability to retard the growth of cultures of human tumor cells.
as·say ( s   , -s)n. 1. Qualitative or quantitative analysis of a substance, especially of an ore or a drug, to determine its components. 2. A substance to be so analyzed. 3. The result of such an analysis. 4. An analysis or examination. v. ( -s, s)1. To subject a substance to chemical analysis. 2. To examine a person's capability by trial or experiment; put to a test. 3. To evaluate a situation; assess. 4. To attempt; try. 5. To be shown by analysis to contain a certain proportion of atoms, molecules, compounds, or precious metal. |
Assay
An analysis of the chemical composition or strength of a substance.
Mentioned in: Parathyroid Hormone Test
assay
[asā′, as′ā]
Etymology: Fr, essayer, to try
the analysis of the purity or effectiveness of drugs and other biologic substances, including laboratory and clinical observations.
assay [as´a]
determination of the purity of a substance or the amount of any particular constituent of a mixture.
biological assay bioassay; determination of the potency of a drug or other substance by comparing the effects it has on animals with those of a reference standard.
CH50 assay a test of total complement activity as the capacity of serum to lyse a standard preparation of sheep red blood cells coated with antisheep erythrocyte antibody. The reciprocal of the dilution of serum that lyses 50 per cent of the erythrocytes is the whole complement titer in CH50 units per milliliter of serum.
enzyme-linked immunosorbent assay (ELISA) any enzyme immunoassay using an enzyme-labeled immunoreactant (antigen or antibody) and an immunoadsorbent (antigen or antibody bound to a solid support). A variety of methods are used for measuring the unknown concentration, such as either competitive binding between the labeled reactant and unlabeled unknown or a sandwich technique in which the unknown antigen binds both the immunoadsorbent and labeled antibody. One of the uses of ELISA is to screen blood for antibody to the human immunodeficiency virus; a positive result indicates probable exposure to the virus and possibly that the virus is in the blood. Since false-positives can occur, a back-up test is used to confirm positive findings.
ELISA: With antigen capture ELISA, the wells are coated with antibody to the virus. The sample containing virus (1) is added and, after washing several times, enzyme conjugated to an antibody to the virus is added (2). Finally, after a further cycle of washing, the enzyme's substrate (3) is added. A colored product is formed if the viral antigen is present in the sample (4). From Hart and Shears, 1997.
microhemagglutination assay–Treponema pallidum (MHA-TP) a Treponema pallidum hemagglutination assay using microtechniques; used in the detection of syphilis.
radioreceptor assay a radioligand assay in which a radiolabeled hormone is used to measure the concentration of specific cellular receptors for the hormone in tissue specimens, an example being radioassay of estrogen receptors in breast tissue.
thyroid-stimulating hormone assay thyroid-stimulating hormone test.
Treponema pallidum hemagglutination assay (TPHA) a treponemal antigen serologic test for syphilis using tanned sheep red blood cells coated with antigen from the Nichol's strain of Treponema pallidum and treated patient serum; it is similar in sensitivity and specificity to the FTA-ABS test. This test is not useful for individuals who have had syphilis in the past.
TSH assay thyroid-stimulating hormone test.
assay
determination of the purity of a substance or the amount or activity of any particular constituent of a mixture.
biological assay
bioassay; determination of the potency of a drug or other substance by comparing the effects it has in a biological system with those of a reference standard.
assay
Lab medicine The quantification of a substance of interest by a specific chemical, enzymatic, immunologic or radioimmune-mediated reaction
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