ABSTRACT
The enzyme-linked immunosorbent assay (ELISA) has emerged as one of the most versatile techniques for the quantitative detection of antibodies specific for bacterial components. The direct ELISA involves the coating of ELISA plates with a purified antigen. The capture ELISA differs from a direct ELISA by using either specific antibodies to the antigen of interest or a preparation of an antigen-receptor, to capture antigen molecules when added to an ELISA plate. The inhibition ELISA is designed to determine whether antibodies, for example, from two different animal species, share specific binding sites on a given antigen or whether two or more antigens express the same epitope. The inhibition ELISA is particularly useful for detecting antibodies to which enzyme-conjugated immunoglobulins are not available, for example, fish immunoglobulins. Hyperimmune rabbit antiserum to a given bacterial antigen is mixed with fish serum and allowed to react with the same antigen coated onto ELISA plates.
