Detection of induced anti-sperm antibodies by an improved enzyme-linked immunosorbent assay.

The enzyme-linked immunosorbent assay (ELISA) has been adapted for the detection of human anti-sperm antibodies (ASA). The use of peroxidase in the enzyme-anti-immunoglobulin conjugate, together with a nontoxic chromogenic substrate (MBTH-DMAB), renders the assay highly sensitive for detection of sperm surface antigens. This ELISA is highly reproducible, not only intra-assay (94% to 97%) but also interassay (80% to 96%). A great advantage of this ELISA is that microplates can be kept at -20 degrees C for months without any decrease in the response. New Zealand white rabbits showed a significant response to human sperm and tail fractions obtained by sonication. The sperm were extremely immunogenic, reaching titers of antisera of 1/10,000 or more. The results show that this ELISA is a good tool for the objective measurement of the anti-sperm response, and is significantly more sensitive than other techniques for anti-sperm antibody analysis.