Detection of anti-spermatozoal antibodies by a super(125)I-protein-A radioimmunobinding assay

A newly developed solid-phase radioimmunobinding assay (RIBA) using detergent-solubilized sperm antigen has been used to evaluate anti-sperm antibodies. Results showed that none of the fertile females and males were positive in the RIBA, whereas approximately 6% of the females and 3% of the males with unexplained infertility were positive. These result are similar to those obtained using a chemically synthesized spermatozoal decapeptide antigen. The RIBA is simple to perform, requires no vital or intact spermatozoa, and large number of sera (up to 400) can be processed in one day with a total incubation time of 90 min.