A convenient and sensitive method for the determination of serum aspartate aminotransferase isozymes after electrophoresis

Abstract

Aspartate aminotransferase (EC 2.6.1.1, AST) isozymes can be separated by electrophoresis into an anionic band, the cytosolic isozyme (c-AST), and a cationic band, the mitochondrial isozyme (m-AST) [ 1-3].Various electrophoretic methods [l] are successful with samples with relatively high AST activity, but their sensitivity is unreliable at very low concentrations of serum m-AST, so often they cannot be used in routine clinical work. Recently, Yagi et al reported a new procedure for staining AST activity after disk gel electrophoresis [4], based on the ability of AST to use cysteine sulfinate as an amino donor in its transamination reaction with cY-ketoglutarate [5]. We developed a simple and sensitive modification of this electrophoretic method that allows accurate differential quantitation of serum AST isozymes, and is convenient for routine clinical work.