Monoclonal anti-type 2 H: an antibody detecting a precursor of the A and B blood group antigens.

A monoclonal antibody was produced which binds specifically to Type 2 H antigen of the ABO blood group system. The antibody, H11, is an IgM molecule which reacts by direct agglutination of red cells with the same pattern as other anti H reagents such as Ulex europaeus lectin. The specificity was determined by inhibition and adsorption with chemically defined oligosaccharides. H11 also reacted with poly (glycosyl) ceramide purified from group 0 red cells and glycoprotein H purified from human stomach mucosa and meconium. H11 differs from Ulex lectin, however, in that it was not inhibited by saliva from ABH secretor individuals or by glycoprotein H purified from human ovarian cysts or submaxillary glands.