Mouse monoclonal antibodies reacting with M blood group‐related antigens

Four mouse monoclonal antibodies were produced with specificities related to human blood group M antigen. The antibodies react in direct hemagglutination systems, and their specificities were investigated by their reactions with variant and enzyme-modified red cells. The effects of temperature and pH on their hemagglutination reactions also were investigated, and all four were murine IgG antibodies. Physicochemical and serologic investigations showed them to be four distinct antibodies, and each one could be used for M blood grouping under appropriate conditions.