CAPTURE ASSAY FOR SPECIFIC IGE - AN IMPROVED QUANTITATIVE METHOD

A capture assay for the measurement of specific IgE in the serum of allergic patients is described, using monoclonal anti-human IgE (coated to the wells of a microtiter plate) and biotinylated allergens in solution. In a single incubation, IgE is bound to the solid phase through the Fc fragment and biotinylated allergens react with their specific IgE Fab regions, if present. In a second step, streptavidin-HRP conjugate is added to reveal the amount of biotin fixed on the solid phase. Quantitative determinations are obtained by comparison with a standard curve of total IgE incubated with a biotinylated monoclonal anti-IgE, complementary to the one employed as capture antibody. The assay is unaffected by allergen-specific IgG, shows good intra- and interassay reproducibility and is linear over a wide range of specific IgE concentrations. The method could be used with a wide range of different allergens.