Species specificity of hybridoma antibodies to surface antigens of guinea pig sperm

Abstract The species specificity of hybridoma antibodies to sperm surface antigens was studied. A collection of over 50 hybridoma antibodies that bind to the guinea pig sperm surface was tested for binding to mouse, rat, hamster, and human sperm by indirect immunofluorescence. None of the antibodies bind to mouse sperm. rat sperm, or human sperm. All but three of the antibodies also fail to bind to hamster sperm. AH‐30, AH‐31, and AH‐1032, the three antibodies that crossreact with hamster sperm, show a different topographical localization on hamster sperm from that seen on guinea pig sperm. The three antibodies do not precipitate a 125I surface‐labeled antigen from hamster sperm extracts. However, from guinea pig sperm extracts, all three antibodies precipitate 125I surface‐labeled polypeptides with molecular weights (Mr) of 62,000, 52,000, and 38,000. This result suggests that the crossreacting antibodies may be recognizing different antigens on hamster and guinea pig sperm.