Phenylthioacetate: a useful substrate for the histochemical and colorimetric detection of cholinesterase.

Cholinesterase from frozen sections of honey bee (Apis mellifera, L.) brain hydrolyzes phenylthioacetate and acetylthiocholine to give virtually identical patterns of enzyme distribution with and without the use of paraoxon. In addition, phenylthioacetate is an economical substrate for in vitro and in vivo studies of cholinesterase. Phenylthioacetate offers the advantages of being easily synthesized and lipoid soluble, and appears to penetrate membranes easily.