There are two general approaches to diagnosing diseases by immunoassays: testing for specific antigens or testing for antigen-specific antibodies. Enzyme linked immunosorbent assays (ELISA), also known as enzyme immunoassays (EIA), are tests designed to detect antigens or antibodies by producing an enzyme triggered color change.
All of the EIAs performed in the Diagnostic Serology Section are known as solid-phase assays. This assay requires the immobilization of antigens or antibodies on solid surfaces such as plastic beads or the wells of microtiter plates.