Semimicrotitration device for cholinesterase assay.

A semimicrotitration device for reaction volumes of 0.5 to 2 ml and effective stirring of reaction solution or suspension is described. The principal part of the device is a combined glass electrode functioning as a reaction vessel (combined "cup"-glass electrode). Characteristics of the device are small volumes and great reliability. Nonspecific cholinesterase activities measured in rat plasma and liver tissue homogenates and compared with the activities of the same tissue and plasma samples measured radiometrically and spectrophotometrically illustrate the applicability of the device. The method is best suited for kinetic studies with multiple substrates of esterases, either in the soluble form or in tissue homogenates.