A marker of human foetal endoderm defined by a monoclonal antibody involves Type 1 blood group chains.

This report demonstrates that a marker of human embryonic endoderm and embryonal carcinoma cells recognized by a hybridoma antibody FC 10.2, involves Type 1 blood group chains with the sequence Gal beta 1 leads to 3G1cNAc beta 1 leads to 3Gal beta 1 leads to 4G1c. This conclusion has been reached from antigenic analyses of meconium, ovarian cyst glycoproteins, oligosaccharides and glycolipids having Type 1 or Type 2 blood group chains. From knowledge of saccharide sequences and blood group related antigens in gastrointestinal tissues of man, we deduce that the 'disappearance' of FC 10.2 antigen from the normal, differentiated cells of the adult may result from masking by additional glycosylations or other substitutions.