radioimmunoassay

ra·di·o·im·mu·no·as·say

R0015200 (rā′dē-ō-ĭm′yə-nō-ăs′ā, -ĭm-yo͞o′-)n. Abbr. RIA A technique used to quantitate minute amounts of a substance, such as a hormone, in blood or another liquid. It involves the use of radioisotopes and of antibodies to the substance being investigated.

radioimmunoassay

(ˈreɪdɪəʊˌɪmjʊnəʊˈæseɪ) n (Medicine) a sensitive immunological assay, making use of antibodies and radioactive labelling, for the detection and quantification of biologically important substances, such as hormone concentrations in the blood

ra•di•o•im•mu•no•as•say

(ˌreɪ di oʊˌɪm yə noʊˈæs eɪ, -æˈseɪ, -ɪˌmyu-)

n. a test procedure that integrates immunologic and radiolabeling techniques to measure minute quantities of a substance, as a drug, in a given sample of body fluid or tissue. [1960–65]

Thesaurus

Noun

radioimmunoassay - immunoassay of a substance that has been radioactively labeledimmunoassay, immunochemical assay - identification of a substance (especially a protein) by its action as an antigen; "PSA in the blood can be measured with an immunochemical assay"

Translations

radioimmunoassay

(RIA), highly sensitive laboratory technique used to measure minute amounts of substances including antigens, hormones, and drugs present in the body. The substance or antigen (a foreign substance in the body that causes antibody production) to be measured is injected into an animal, causing it to produce antibodies. Serum containing the antibodies is withdrawn and treated with a radioactive antigen and later with a nonradioactive antigen. Measurements of the amount of radioactivity are then used to determine the amount of antigen present. The technique was developed by Solomon Berson and Rosalyn YalowYalow, Rosalyn Sussman,
1921–2011, American medical physicist, b. New York City, Ph.D. Univ. of Illinois, 1945. As a researcher at the Bronx Veterans Administration Hospital (from 1947), Yalow and colleague Solomon A.
..... Click the link for more information. . Yalow was awarded the 1977 Nobel Prize in Physiology or Medicine for her work.

Radioimmunoassay

A general method employing the reaction of antigen with specific antibody, permitting measurement of the concentration of virtually any substance of biologic interest, often with unparalleled sensitivity. The basis of the method is summarized in the competing reactions shown in the illustration. The unknown concentration of the antigenic substance in a sample is obtained by comparing its inhibitory effect on the binding of radioactively labeled antigen to a limited amount of specific antibody with the inhibitory effect of known standards.

Competing reactions that form basis of radioimmunoassay; ^* indicates the labeled antigen, and † “in known standard solutions or unknown samples

A typical radioimmunoassay is performed by the simultaneous preparation of a series of standard and unknown mixtures in test tubes, each containing identical concentrations of labeled antigen and specific antibody. After an appropriate reaction time the antibody- bound (B) and free (F) fractions of the labeled antigen are separated by one of a variety of techniques. The B/F ratios in the standards are plotted as a function of the concentration of unlabeled antigen (standard curve), and the unknown concentration of antigen is determined by comparing the observed B/F ratio with the standard curve.

The radioimmunoassay principle has found wide application in the measurement of a large and diverse group of substances in a variety of problems of clinical and biological interest. It is therefore not unexpected that there are differences in the specific methods employed for the assay of a particular substance. The full potential of the method has yet to be exploited. It seems that virtually any substance of biologic interest can be measured, the method being modified according to the characteristics of the particular substance. See Antibody, Antigen, Immunology

radioimmunoassay

[¦rād·ē·ō¦im·yə·nō′a‚sā] (immunology) A sensitive method for determining the concentration of an antigenic substance in a sample by comparing its inhibitory effect on the binding of a radioactivity-labeled antigen to a limited amount of a specific antibody with the inhibitory effect of known standards.

radioimmunoassay

(RIA) [ra″de-o-im″u-no-as´a] a sensitive assay method that can be used for the measurement of minute quantities of specific antibodies or any antigen, such as a hormone or drug, against which specific antibodies can be raised. An assay for a specific hormone uses antihormone antibody produced by injecting the human hormone into an animal, such as a rabbit, and hormone that has been labeled with a radioisotope. These are mixed with the assay specimen and the antigen (hormone) bound to antibody is separated from the unbound antigen by chromatography or other means. Because any hormone in the assay specimen competes with the radiolabeled hormone for antibody binding sites, the amount of hormone in the specimen is inversely proportional to the radioactivity of the bound fraction or directly proportional to the activity of the free fraction. This is the standard method for clinical laboratory measurements of hormones and is also used for therapeutic drug monitoring, drug abuse screening, and other laboratory tests.

ra·di·o·im·mu·no·as·say (RIA),

(rā'dē-ō-im'yū-nō-as'sā), An immunologic (immunochemical) procedure that uses competitive inhibition between a radioisotope-labeled antigen or other substance and unlabeled antigen for antiserums, binding as a means to quantify the agent of interest; any method for detecting or quantitating antigens or antibodies using radiolabeled reactants. Minute quantities of enzymes, hormones, or other substances can be assayed.

radioimmunoassay

(rā′dē-ō-ĭm′yə-nō-ăs′ā, -ĭm-yo͞o′-)n. Abbr. RIA A technique used to quantitate minute amounts of a substance, such as a hormone, in blood or another liquid. It involves the use of radioisotopes and of antibodies to the substance being investigated.

radioimmunoassay

see RIA.

ra·di·o·im·mu·no·as·say

(RIA) (rā'dē-ō-im'yū-nō-as'sā) An immunologic (immunochemical) procedure that uses the competition between radioisotope-labeled antigen (hormone) or other substance and unlabeled antigen for antiserums, resulting in quantitation of the unlabeled antigen; any method for detecting or quantitating antigens or antibodies using radiolabeled reactants.

radioimmunoassay

Any method of measuring the extent of linkage between ANTIGEN and ANTIBODY in which one or other of these is labelled with a radioactive substance (radionuclide). Measurement of radiation can be remarkably precise.

radioimmunoassay

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ra·di·o·im·mu·no·as·say (RIA),

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Words related to radioimmunoassay

noun immunoassay of a substance that has been radioactively labeled

Related Words