“…It has been based on changes in sperm morphology after enzyme extraction (Pedersen, 1972;Brown & Hartree, 1974;Churg et al, 1974;Srivastava et al, 1974), on the localization of labelled non-specific enzyme inhibitors (Stambaugh & Buckley, 1972) and on the detection of proteolytic activity using gelatin films (Gaddum & Blandau, 1970;Benitez-Bribiesca & Velazquez-Meza, 1972;Gaddum-Rosse & Blandau, 1972;Penn et al, 1972;Allen et al, 1974). This proteolytic activity is unlikely to be specific as there is increasing evidence that more than one proteinase exists in spermatozoa (Dott & Dingle, 1968;Allison & Hartree, 1970;Multimaki & Niemi, 1972;Yanagimachi & Teichman, 1972;Bernstein & Teichman, 1973;Srivastava & Foley, 1973). Another approach to the problem lies in the use of monospecific antisera to localize a particular enzyme.…”