Solid‐Phase Indirect Immunogold Localization of Human Sperm Antigens Reacting with Antisperm Antibodies in Human Sera

Abstract

A simple solid‐phase indirect immunogold assay for light microscopic localization of the binding of sperm‐reactive antibodies in human sera to surface‐associated antigenic sites on human sperm is described. Antigen‐antibody interaction is localized by using a gold‐tagged second antibody directed against the first antibody. Silver enhancement of the 5 nm gold particles makes the immunologic reaction visible by light microscopy. An ELISA was used to identify serum samples as positive or negative for sperm‐reactive antibodies. These serum samples were blind‐coded and were used to develop and to evaluate this solid‐phase indirect immunogold assay. When results obtained by this immunogold assay for the detection of sperm‐reactive antibodies were compared with those obtained by the ELISA, there was agreement in 82 of the 100 sera tested. As a localization assay, this indirect immunogold assay is simple to perform and enables stable, high resolution light microscopic localization of the pattern of antigenic sites on sperm surface membranes.