Cholinesterase and Organophosphate Detection Reagents

Cholinesterase assays have a multitude of applications including human diagnostics, drug discovery, food, environmental, and chemical terrorism detection.

In human diagnostics, cholinesterase activity and inhibition is used as an indicator for organophosphate (OP) exposure or predisposed cholinesterase deficiency. The presence of acetylcholinesterase in amniotic fluid may indicate birth defects, including abdominal wall and neural tube defects.

In pharmaceutical applications, cholinesterase inhibitors are potentially useful in early and moderate stages of Alzheimer′s Disease to increase levels of acetycholine in the brain or by improving cellular response. Absence or mutation of butyrylcholinesterase can result in apnea after administration of muscle relaxants such as succinylcholine or Micacuriu. Reduced butyrylcholinesterase levels may be an indicator of advanced liver disease, whereas elevation may indicate acute myocardial infarction.

Detection and quantitation of organophosphate pesticides and chemical nerve agents is typically performed in the laboratory using LC-MS. However, enzymatic-based assays provide a convenient alternative.

Enzymatic methods for measuring organophosphate and cholinesterase activity include:
Colorimetric (Using DTNB or ferricyanate to measure thiolesterase products)
Colorimetric (coupled with choline oxidase and peroxidase)
Titrimetric (mainly for purified enzyme activity assays)

by increasing the levels in the brain or by strengthening the way nerve cells respond to it. Increased concentrations of acetylcholine in the brain lead to increase communication