The enzyme-linked immunosorbent assay (ELISA) (/ɨˈlaɪzə/, /ˌiːˈlaɪzə/) is a test that uses antibodies and color change to identify a substance.ELISA is a popular format of "wet-lab" type analytic biochemistry assay that uses a solid-phase enzyme immunoassay (EIA) to detect the presence of a substance, usually an antigen, in a liquid sample or wet sample.The ELISA has been used as a diagnostic tool in medicine and plant pathology, as well as a quality-control check in various industries.Antigens from the sample are attached to a surface.