Biochemical test for a protein or other molecule using an antibody
Immunoassay
Illustration of the basic components of an immunoassay, which includes an analyte (green), an antibody (black), and a detectable label (yellow)
MeSH
D007118
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An immunoassay (IA) is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the use of an antibody (usually) or an antigen (sometimes). The molecule detected by the immunoassay is often referred to as an "analyte" and is in many cases a protein, although it may be other kinds of molecules, of different sizes and types, as long as the proper antibodies that have the required properties for the assay are developed. Analytes in biological liquids such as serum or urine are frequently measured using immunoassays for medical and research purposes.[1]
Immunoassays come in many different formats and variations. Immunoassays may be run in multiple steps with reagents being added and washed away or separated at different points in the assay. Multi-step assays are often called separation immunoassays or heterogeneous immunoassays. Some immunoassays can be carried out simply by mixing the reagents and samples and making a physical measurement. Such assays are called homogeneous immunoassays, or less frequently non-separation immunoassays.
The use of a calibrator is often employed in immunoassays. Calibrators are solutions that are known to contain the analyte in question, and the concentration of that analyte is generally known. Comparison of an assay's response to a real sample against the assay's response produced by the calibrators makes it possible to interpret the signal strength in terms of the presence or concentration of analyte in the sample.
^Yetisen A. K. (2013). "Paper-based microfluidic point-of-care diagnostic devices". Lab on a Chip. 13 (12): 2210–2251. doi:10.1039/C3LC50169H. PMID 23652632.
An immunoassay (IA) is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the...
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(2018-04-20). "Comparison of electrochemiluminescence immunoassay and latex agglutination turbidimetric immunoassay for evaluation of everolimus blood concentrations...
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seroconversion) are usually considered non-infectious. HBsAg detection by immunoassay is used in blood screening, to establish a diagnosis of hepatitis B infection...
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employment, poisoning diagnostics, and forensics. Techniques such as immunoassay, which is the most common form of amphetamine test, may cross-react with...
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poisoning, or assist in a medicolegal death investigation. Many commercial immunoassay screening tests directed at the amphetamines cross-react appreciably...
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drug was taken or how much the patient used. Urine drug testing is an immunoassay based on the principle of competitive binding. Drugs which may be present...
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