Determination of Serum Lactic Dehydrogenase Isoenzymes by Use of the "Diagnostest" Cellulose Acetate Electrophoresis System

Abstract

A method is described for measuring serum lactic dehydrogenase isoenzymes by use of a commercial electrophoresis system. Six samples are simultaneously electrophoresed on cellulose acetate plates to separate the five isoenzymes, which are made visible by overlaying and incubating the electrophoresed plate with another plate saturated with lactate, phenazine methosulfate, and INT (a tetrazolium dye). The pattern is qualitatively assessed, or the plates are made transparent with dimethylsulfoxide— propanol and the isoenzymes measured densitometrically. The normal range for each isoenzyme, determined on 39 nonmedicated, nonfasting men and women, agrees with reported values. Duplicate plates are obtained for each serum analyzed. The entire procedure requires 2 h.