Abstract
Non-specific esterases of the normal mouse epididymis have been studied by the a-naphthyl acetate (α-NA) and 5-bromoindoxyl acetate (5-BIA) methods and by these techniques in combination with inhibitors. These studies demonstrate that several esterase isozymes are present in the epididymis. The a-NA method produces a strong reaction to at least one isozyme more than is demonstrable by 5-BIA. The latter technique thus distinguishes between different cells which show identical reaction to α-NA. The use of inhibitors confirms these differences. The techniques used enable localization of the cells of origin of various isozymes in a complex organ. The results provide a basis for studies on the genetical control of cell function.