Automated enzyme-linked fluorescence immunoassays for antiviral antibodies: a test for anti-HBs.

A solid-phase enzyme-linked fluorescence immunoassay (ELFA) for antiviral antibodies using antigen covalently linked to Escherichia coli beta-galactosidase and a fluorogenic substrate (4-methyl-umbelliferyl-beta-D-galactopyranoside) is described. Antibodies to hepatitis B surface antigen (HBsAg) from test samples were adsorbed to wells of 96-well aminopolystyrene plates precoated with HBsAg. The antibodies were subsequently detected using enzyme-conjugated HBsAg. The measurement of fluorescence was automated. The sensitivity of the test was approximately 50 times higher than that of a commercial radioimmunoassay.