Spermotoxic properties of IgG fractions from normal rabbit sera

The antisperm activities of IgG fractions prepared from normal rabbit sera by three different techniques (ammonium sulphate precipitation, gel filtration, and DEAE-Sephadex absorption) were tested using a cytotoxic assay, and antisperm activity detected in fractions prepared by each of these techniques. The nature of the interactions between sperm and IgG molecules from normal sera, and possible functions of "natural" antisperm antibodies, are discussed.