Abstract
A sensitive enzyme immunoassay for anti-β-lactoglobulin immunoglobulin G (IgG) in serum is described. Serum containing anti-β-lactoglobulin IgG was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-β-lactoglobulin conjugate and β-lactoglobulin-peroxidase conjugate. The complex formed from the three components was trapped onto polystyrene balls coated with anti-2,4-dinitrophenyl group IgG, eluted with ε-2,4-dinitrophenyl-L-lysine and transferred to polystyrene balls coated with anti-human IgG-γ-chain IgG. Bound peroxidase activity was determined by fluorometry. This enzyme immunoassay was 100- to 1000-fold more sensitive and more reliable than the enzyme-linked immunosorbent assay (ELISA). Anti-β-lactoglobulin IgG was detected in 91% of healthy subjects using this method.