Faecal chymotrypsin--a new photometric method using N-acetyl-L-tyrosine ethyl ester as substrate

A photometric method for chymotrypsin is proposed, using the substrate N-acetyl-L-tyrosine ethyl ester, which is already used in the titrimetric procedure. Hydrolysis of the ester bond produces equal amounts of ethanol and acetyltyrosine, the latter being measured in the titrimetric method. The ethanol can easily be measured by the alcohol dehydrogenase method in the trichloroacetic acid supernatant. Suitable test conditions are reported.