A simple method for determining specific esterase activity in tissue extracts.

A simple procedure for estimating specificB-naphthyl esterase enzyme content and activity in small amounts of crude tissue extract is described. Esterase activity is determined by quantitative densitometry of histochemically stained acrylamide gels. Activity measured this way is linear with the extract volume applied. Esterase content is determined by isotopic labeling with a stoichiometric covalently binding enzyme inhibitor, diisopropylfluorophosphate; followed by electrophoresis and gel slice counting.