Carbohydrate-enzyme conjugates for competitive EIA.

Enzyme glycoconjugates prepared from oligosaccharides or polysaccharides are efficient and durable reagents for direct, competitive enzyme immunoassays based on solid phase antibody. This assay format facilitates simple measurement of association constants and relative inhibitory power of oligosaccharides, while also providing a sensitive quantitative assay of bacterial polysaccharide antigens. Enzyme-saccharide conjugates were prepared by established glycoconjugate methodologies, and protocols for their optimal use were established by investigating the effects of solid phase antibody concentration on the kinetic equilibrium of binding for different antigen-enzyme conjugate concentrations, in the presence and absence of inhibitor. Four discrete monoclonal antibody-carbohydrate antigen systems were studied and it is demonstrated for each, that the relative inhibitory power of oligosaccharides may be readily measured in a convenient assay format, and that association constants can be extrapolated from the same assay data.