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Enzyme Linked Immuno Absorbant Assay
ELISA is an acronym for Enzyme-Linked Immuno Sorbent Assay. It is a biochemical assay widely used to detect the presence of and quantity of a particular protein in a sample, such as hormones, antibodies, and bacteria or viruses.
The assay uses the coupling of antigens and antibodies and relies on the specificity (the ability to discriminate among diverse proteins) and affinity (the ability to tightly bind to molecules) of antibodies for antigens.
Using the ELISA method, one can determine how much antibody is present in a sample by starting with an antigen, or one can determine how much antigen is present in a sample by starting with the antibody.
AIDS can be detected using this procedure. Antigen-antibody reaction is the underlying principle in this test.