A radiomicroassay for cytotoxic antibody to human spermatozoa. Quantification by tritiated actinomycin d

A radiomicroassay for titration of spermocytotoxic antibody is described. The assay used [3H]AACTINOMYCIN D ([3H]Act D) to label damaged spermatozoa in a fashion analogous to penetration by vital dye. Optimal conditions for and some kinetics of the assay are presented. The assay is sensitive, reliable, simple to perform and uses only small amounts of serum and spermatozoa. Applied to sperm antibody positive human postvasectomy sera, the assay compared favourably in sensitivity eith vital dye microscopic observations and with parallel titration by the Isojima's immobilization tests.