TRAP

TRAP

(trap),

Acronym for twin reversed arterial perfusion.

A regional term for hiding place for drugs

assay

(as'a?, a-sa') [Fr. assai, trial]

The analysis of a substance or mixture to determine its constituents and the relative amount of each.

anti-Xa assay

A test that monitors blood clotting in patients taking anticoagulant drugs, such as low molecular weight heparin or unfractionated heparin. Heparins bind to antithrombin, which inhibits clotting factor Xa. The degree to which factor Xa is inhibited is measured by this assay.

biological assay

Bioassay.

chromogenic assay

Any laboratory test that relies on the change in color of a reagent to indicate its presence.

enzyme-linked immunosorbent assay

Abbreviation: ELISA

The former name for “enzyme immunoassay.”

See: enzyme immunoassay

fetal fibronectin assay

Abbreviation: fFN

A screening test that identifies the probability of preterm labor. Fibronectin, a cold insoluble globulin, is usually found in cervicovaginal fluid during the first 20 weeks of pregnancy. It is then undetectable until about gestational week 34. A positive fFN test result in women with symptoms of threatened preterm labor indicates the probability of delivery within 1 week. Aggressive treatment of threatened preterm labor with tocolytics and corticosteroids increases potential for fetal survival.

gel mobility shift assay

Electrophoretic study in a gel that permits the identification of interactions between DNA and other molecules, such as receptor proteins, based on their differential movement.

hormone assay

A blood test to assess endocrine system status.

immunodot assay

An antigen detection tool in which droplets containing antibodies to a specific antigen are dried on strips of nitrocellulose. Samples of body fluids from patients are exposed to these antibodies. A chemical or fluorescent reaction from binding of the antigen is used to suggest its presence in the tested sample. Immunodot assays are used, e.g., in rapid tests for the presence of influenza, pneumococcal pneumonia, malaria, and strep throat.

immunoradiometric assay

Abbreviation: IRMA

Radioassay in which an antibody is labeled with a radioactive tracer. Antigens are detected when they bind, reversibly, to the antibody.

interferon gamma assay for tuberculosis

Any test for latent tuberculosis that relies on the amount of interferon gamma (IFN?) released by T cells that have been previously exposed to mycobacterial antigens. One such test, the whole blood assay, is performed by withdrawing about 1 ml of whole blood from the vein of a patient. This blood is heparinized, to prevent clotting, and then mixed with specific mycobacterial antigens and control substances. After overnight incubation, samples of plasma from the blood are tested for INF? levels. The test is considered positive if INF? in a sample exposed to mycobacterial antigens is > 0.35 IU/ml.

intracellular killing assay

A laboratory test of bacterial ingestion by phagocytes. Neutrophils or macrophages are placed in a culture with bacteria. After 30 min, the remaining bacteria are killed with an antibiotic, and the phagocytes are stained and examined for the number of bacteria they have ingested. This assay is only accurate if the phagocytes have been tested previously for the ability to ingest bacteria.

Synonym: neutrophil microbicidal assay

neutrophil microbicidal assay

Intracellular killing assay.

plasma very long-chain fatty acid assay

Abbreviation: VLCFA assay

A blood test to detect adrenoleukodystrophy in infants or adrenomyeloneuropathy in adults with progressive paraparesis.

serotonin release assay

A laboratory test for diagnosing heparin-induced thrombocytopenia. Platelets from a patient suspected of having the disease are mixed with healthy platelets labeled with radioactive serotonin. The release of radiolabeled serotonin after exposure to therapeutic doses of heparin constitutes a positive test.

sperm penetration assay

A test to evaluate male fertility in which a sample of sperm is added to hamster eggs whose zona pellucida has been removed. The number of sperm that penetrate each egg is measured and compared to a normal value. Synonym: hamster zona-free ovum test

tandem mass assay

Tandem mass spectrometry.

telomeric repeat amplification protocol assay

Abbreviation: TRAP

A means of detecting telomerase activity in laboratory specimens. Telomerase can be used as a biomarker for the presence of malignant cells. TRAP has been used to detect abnormal telomerase activity in urine (a marker of bladder cancer) and in tissue and cell extracts, e.g., in lymphomas or renal tumors.

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telomeric repeat amplification protocol assay

Abbreviation: TRAP

A means of detecting telomerase activity in laboratory specimens. Telomerase can be used as a biomarker for the presence of malignant cells. TRAP has been used to detect abnormal telomerase activity in urine (a marker of bladder cancer) and in tissue and cell extracts, e.g., in lymphomas or renal tumors.

See also: assay