ELISA

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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.

ELISA

(ĕ-lē'să),

ELISA

(ĭ-lī′zə, -sə)
n.
A sensitive immunoassay that uses an enzyme linked to an antibody or antigen as a marker for the detection of a specific protein, especially an antigen or antibody. It is often used as a diagnostic test to determine exposure to a particular infectious agent, such as the AIDS virus, by identifying antibodies present in a blood sample.
Enzyme-Linked Immunosorbent Assay. An immunoenzymatic assay used to measure antigens and antibodies which approaches the sensitivity of RIA
Pros Lower cost, simpler equipment, faster ‘turn-around time’, and none of the problems inherent in handling radioactive substances

ELISA

Enzyme-linked immunosorbent assay Lab medicine A heterogeneous immunoenzymatic assay that approaches the sensitivity of RIA Pros Lower cost, simpler equipment, faster 'turn-around time', and none of the problems inherent in handling radioactive substances; ELISA may be used to measure any antigen and antibody. See Avidin-biotin method, EMIT, RIA, Sandwich method.

ELISA

Abbreviation for enzyme-linked immunosorbent assay.

ELISA

see ENZYME-LINKED IMMUNOSORBENT ASSAY.

ELISA

Enzyme-linked immunosorbent assay. This test has been used a screening test for AIDS for many years and has also been used to detect gonorrhea bacteria.
Mentioned in: Gonorrhea
References in periodicals archive ?
Since it is the practice in the US to treat this cause of pharyngitis, current recommendations for diagnosis state that a confirmatory culture should be obtained in patients with a negative rapid strep antigen test. This strategy can be cumbersome in clinical practice, may delay treatment, and result in unnecessary use of antibiotics while awaiting culture results.
pneumophila urinary antigen test should not be used to rule out L.
The most commonly described methods of virus testing are immunochromatographic rapid antigen tests, nucleic-acid-amplification-based tests, immunoflourescence-based tests, and virus culture.
Using only the suppurative complications in patients who received culture or rapid antigen test before the visit, the study would have the power to detect an increase of 0.08% to 0.19%.
The overall sensitivity of rapid antigen tests for group A streptococcus has declined in recent years.
Contract awarded for Ai purchase of emergency antiretroviral antigen test material (northern branch)
pneumophila serogroup 1 by specific urinary antigen test and culture, but they recovered and were discharged.
More men are asking to have a prostate specific antigen test, which is available to men over 50.
For adults, guidelines that recommend against testing those with a low clinical likelihood of GAS infection and against using throat culture to confirm negative rapid antigen test results could lead to a substantial number of missed GAS pharyngitis cases, while selective use of throat cultures is compatible with a goal of reducing antibiotic use and unnecessary prescribing of antibiotics.
Until then, not following a negative rapid antigen test for Streptococcus--more commonly known as group A streptococcus--with a traditional laboratory culture may put patients at risk for serious sequelae, he said.
In our study, we compared streptococcal complication rates at a large suburban medical center during 2 time periods: when pharyngitis patients were managed almost exclusively with throat culture and when they were managed primarily with a high-sensitivity antigen test without culture confirmation of negative results.
30% - 34% Plasma/serum tests for drugs of abuse; rapid tests or urinary tract infections; serum cholesterol testing; Neisseria gonorrhoea presumptive identification; rapid tests for measles; Giardia antigen test. 25% - 29% Cryptosporidium antigen tests; Giardia microscopy; high-volume water sampling for enteric pathogens; HIV, indirect immunofluorescence (IIF); Chlamydia antigen EIA; Chlamydia DNA PCR; gonorrhea disk diffusion; Listeria culture; hepatitis B antigen; tests for hepatitis C virus.