Quantification and phenotyping of serum cholinesterase by enzyme antigen immunoassay: methodological aspects and clinical applicability.

An enzyme antigen immunoassay for a specific determination of serum cholinesterase is described. Polyclonal and monoclonal antibodies against cholinesterase have been used. Hydrophobic binding of the specific antibody to a microtitre plate was followed by incubation with the samples, and the activity of the bound cholinesterase was assayed by the Ellman method. The procedure has been optimized and characterized, with respect to antigen specificity, and the applicability of the assay for cholinesterase phenotyping is demonstrated. The cholinesterase activities, dibucaine-, scoline-, fluoride- and urea numbers were comparable with established reference values. The high sensitivity and specificity of the assay has been used for determination of cholinesterase in amniotic and cerebrospinal fluids, and its applicability in clinical medicine is indicated.