The Test-mate ChE Cholinesterase Test System is on the basis of Ellman
method. Acetylthiocholine (AcTC) or butyrylthiocholine (BuTC) is hydrolyzed by
AChE or PChE, respectively, producing carboxylic acid and thiocholine with reaction
to the Ellman reagent (DTNB, dithionitrobenzoic acid) so as to create a yellow color
that is gauged spectrophotometrically at 450 nm. The rate of color formation is in
proportion to the amount of either AChE or PChE (EQM Research, Inc., 2003).