Production and characterization of a monoclonal antibody to ABH-carrying alpha 2-seminoglycoprotein for ABO grouping of semen by ELISA.

BALB/c mice were immunized with alpha 2-seminoglycoprotein (A2SGP), the lymph node cells were fused with P3U1 myeloma cells and cultured by the conventional technique. Four antibody-producing hybridoma clones were established and antibody-containing ascitic fluid obtained. The antibody was directed to the protein backbone of A2SGP and not to ABH antigenic determinants and did not cross-react with saliva or vaginal secretions. When tested in an indirect ELISA the anti-A2SGP antibody had a titer of 512000. The anti-A2SGP was used in a capture ELISA (or sandwich ELISA) in which wells were coated with this antibody to capture A2SGP in semen, and the captured A2SGP was detected with anti-A, anti-B or anti-H-peroxidase conjugate and peroxidase-labeled second antibody. This ELISA allowed correct ABO grouping even of 1:12,800 or higher dilutions of semen. When the ELISA was applied to ABO grouping of seminal fluids mixed with vaginal secretions only the seminal ABH antigens could be detected. The results strongly suggest the potential usefulness of monoclonal anti-A2SGP in the investigation of rape cases.