Evaluation of the UV-340 Spectrophotometric Determination for Pseudocholinesterase Activity (EC 3.1.1.8) in Human Serum

Abstract

A pseudocholinesterase catalytic activity assay using /7-hydroxybenzoylcholine äs Substrate and measuring the decrease of NADPH at 340 nm was compared with a colorimetric method using acetylthiocholine äs Substrate. s The assay is simple, uses 50 serum and is performed at 37 °C. Precision of the UV-340 method was good except at low ranges. The catalytic activity was depressed by the anticoagulants citrate and fluoride but not by EDTA or heparin. The reference values obtained with the evaluated UV-340 method are somewhat higher than those with the colorimetric method.As the results with both methods are comparable, the choice of procedure will depend on the local facilities.