Medicine/Medical. a sensitive diagnostic test for past or current exposure to an infectious agent, as the AIDS virus: a sample of blood is added to proteins from the agent, and any antibodies that combine with the proteins, indicating a history of infection, are detected by adding a test antibody linked to an enzyme that causes a color change.
Biology, Medicine/Medical. any similar test using proteins as a probe for the identification of antibodies or antigens.
ELISA (ĭ-lī'zə, -sə) n. Enzyme-linked immunosorbent assay; a sensitive immunoassay that uses an enzyme linked to an antibody or antigen as a marker for the detection of a specific protein, especially an antigen or antibody.