enzyme-linked immunosorbent assay

assay /as·say/ (as´a) determination of the amount of a particular constituent of a mixture, or of the potency of a drug.

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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.

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enzyme-linked immunosorbent assay

n.

ELISA.

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Enzyme-linked immunosorbent assay (ELISA)

A diagnostic blood test used to screen patients for AIDS or other viruses. The patient's blood is mixed with antigen attached to a plastic tube or bead surface. A sample of the patient's blood serum is added, and excess proteins are removed. A second antibody coupled to an enzyme is added, followed by a chemical that will cause a color reaction that can be measured by a special instrument.

Mentioned in: AIDS Tests, Giardiasis

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enzyme-linked immunosorbent assay (ELISA),

a laboratory technique for detecting specific antigens or antibodies by using enzyme-labeled immunoreactants and a solid-phase binding support, such as a test tube. A number of different enzymes can be used, including carbonic anhydrase, glucose oxidase, and alkaline phosphatase. Labeling is done by covalently binding the enzyme to the test substance through an enzyme-protein coupling agent such as glutaraldehyde. Products of the reaction may be detected by fluorometry or photometry. ELISA is nearly as sensitive as radioimmunoassay and more sensitive than complement fixation, agglutination, and other techniques. It is commonly used in the diagnosis of human immunodeficiency virus infections.

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enzyme-linked immunosorbent assay (enˑ·zīm-linkd′ imˈ·myun·ō·sorˑ·bnt aˑ·say),

n technique used to identify particular antibodies or antigens using enzyme-labeled immunoreactants. Reaction products are recorded by photometry or fluorometry. Commonly used to diagnose HIV infections.

Enzyme-linked immunosorbent assay.

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enzyme (en´zīm),

n a protein substance that acts as a catalyst to speed up metabolic and other processes involving organic materials. Some enzymes function within cells; others function in the extracellular fluids and tissue spaces and organs. They are active in all major tissue functions, such as cellular respiration, muscle contraction, digestive processes, and energy consumption, and are produced intracellularly.

enzyme-linked immunosorbent assay (ELISA),

n a species-specific serologic laboratory procedure used to identify microorganisms infecting or inhabiting a tissue or organ system. Its dental use is in the identification of pathogens involved in periodontal disease.