Determination of cholinesterase activity in brain and blood samples using a plate reader

A rapid method is described for the quantitative determination of cholinesterase activity in large batches of blood and brain samples. The technique is an adaptation of the Ellman procedure for a 96-well microtiter plate reader. Ten samples can be analyzed simultaneously in 5 min, with all calculations, including statistical analysis, done automatically. The method detection limit is 0.1 microM/mL/min for blood and 0.1 microM/g/min for brain samples. The procedure has been applied to the routine analyses of samples presented to the veterinary diagnostic laboratory. Method performance, quality control, and normal ranges of cholinesterase activity in livestock and other animals are described.