Monoclonal antibodies against blood group A secretors and nonsecretors saliva.

To obtain monoclonal antibodies (MAbs) that distinguish secretor and nonsecretor from their saliva in forensic casework, two (K7405 and K7422) and one (K7516) MAbs reacting to blood group A antigen were produced by immunization of mice with salivary mucin obtained from blood group A secretors and nonsecretors, respectively. K7405, produced by immunization with salivary mucin obtained from A secretor, reacted with the A substances bound to the carrier protein but not with the A substance separated from the carrier protein. On the other hand, the K7422 and K7516 were reactive to the A substance separated from carrier protein. From these results, we conclude that K7405 recognizes the A substances clustered on the carrier protein and K7422 and K7516 recognize the isolated A substance. In the forensic blood typing of body fluids, A secretors and A nonsecretors can be clearly discriminated by the combined application of two MAbs (K7405 and K7516), which react differently against saliva samples.