Enzyme-linked fluorescence immunoassays using beta-galactosidase and antibodies covalently bound to polystyrene plates.

A solid-phase enzyme-linked immunoassay using a fluorogenic substrate (4-methylumbelliferyl-beta-D-galactopyranoside) was developed. Antibodies were covalently linked to glutaraldehyde-activated 96-well aminopolystyrene plates. Antigens from test samples were adsorbed to the solid phase and detected using antibodies conjugated with E. coli beta-galactosidase. Glutaraldehyde, N-succinimidyl-3-(2-pyridyldithio)-propionate or N-succinimidyl-6-(4-azido-2-nitrophenylamino)-hexanoate were used as linkers between antibodies and the enzyme. The measurement of fluorescence can be automated for rapid screening of many specimens. The sensitivity limit of the test for HBsAg is about 5-10 pg.