Nonspecific esterases in leukemic blasts. Characterization by isoelectric focusing in polyacrylamide gel.

Using high-resolution technics of isoelectric focusing in polyacrylamide gel, isoenzymatic components of nonspecific esterases extracted from various cytologic types of leukemic blasts were visualized using alpha-naphthyl acetate and alpha-naphthyl butyrate as substrates. For each cytologic type of leukemic blast, consistent and distinctive patterns of nonspecific esterase activity were visualized. These studies provide further evidence for heterogeneity of nonspecific esterases, and for elaboration of isoenzymatic components as a reflection of cellular differentiation.