Precipitating monoclonal antibodies to 1 of the antigenic determinants of streptococcal group-A polysaccharide

Monoclonal antibodies (MCA) to streptococcal group A polysaccharide (A-PS) were prepared. Precipitating MCA are directed to the determinant common for A-PS and streptococcal group L polysaccharide (L-PS). The antibodies react in the immunodiffusion test and give identity reaction in A- and L-PS tests. Other MCA are non-precipitating but react with A-PS studied by immunoenzyme method. The reasons for the formation of precipitating and non-precipitating MCA to different antigenic determinants of A-PS are discussed.