Monoclonal antibody against an amniotic protein carrying ABH blood group epitopes and its forensic application.

A mouse monoclonal antibody against an amniotic protein carrying ABH antigenic epitopes was established. BALB/c mice were immunized by an amniotic protein of molecular weight over 200 kDa, which had proved to be the carrier protein of ABH blood group epitopes by analysis with SDS-PAGE and immunoblotting. The antibody, ASP-1, was directed to the amniotic carrier protein without affecting the ABH blood group antigenicity, and did not cross-react with other body fluids which included blood, saliva, semen, urine or vaginal secretion. The immunoglobulin class of ASP-1 was IgG1 with a titer of 1 : 1,600. ASP-1 was used to detect the ABH blood group of amniotic fluid by the sandwich ELISA in which wells of plates were coated with ASP-1, and the ABH blood group of the captured protein was detected with mouse IgM anti-A and -B antibodies and enzyme conjugated anti-mouse IgM. The sandwich ELISA could successfully detect the blood group of amniotic fluid in mixed body fluids.