Determination of cholinesterase in blood and tissue.

The widespread use of organophosphate and organocarbamate pesticides and the dangers of related chemical warfare agents dramatize the importance of rapid, accurate, and sensitive assays for blood and tissue cholinesterases (ChEs), important targets for neurotoxic chemicals. Two ChE enzymes used as biomarkers of exposure are the specific acetylcholinesterases (AChE, EC 3.1.1.7) and the nonspecific plasma cholinesterases (BChE, EC 3.1.1.8). This unit contains two protocols for measuring ChE activity: (1) a colorimetric kinetic method and (2) a radiometric endpoint assay and selective inhibitors that are used to distinguish between the two classes of enzymes.