Quantitative determination of acetylcholinesterase by enzyme antigen immunoassay: methodological aspects and clinical use.

We here describe the optimization of an immunochemical measuring method for acetylcholinesterase (AChE) found in different human body fluids. The principle is the binding of a polyclonal antibody to a solid support (microtitre plate), followed by quantitation of the enzymatic active antigen, by its own enzymatic activity. The test is mainly thought as a diagnostic tool for the prenatal detection of neural tube defects (NTD). The assay is optimized with respect to antibodies and a number of physical parameters. The test is accurate and reliable, and it yields quantitative results. Further we show it to give neither false positive nor false negative values in the prediction of NTD. The assay also performs well on other sample-materials. We suggest that the test will be routinely used alongside amniotic alpha-fetoprotein (AFP) determinations to ensure the correct prenatal diagnosis of NTD.