An enzyme-linked immunosorbent assay (hence the acronym) which can readily measure less than a nanogram (10-9g) of a protein. This assay is more sensitive than simple immunoassay (tests) because one of the two antibodies used to bind and quantitate (measure) the protein’s antigen, based on two concurrent epitopes within the protein, is attached to an enzyme. The enzyme can rapidly convert an added colorless substrate into a colored product, or a nonfluorescent substrate into an intensely fluorescent product (thus enabling finer quantitation).
The enzyme-linked immuno-absorbent assay, a rapid screening test used to detect antibody to human immunodeficiency virus (HIV).