Aspartate aminotransferase isozymes in plants: Comparison of two staining methods in polyacrylamide gels

Two staining methods for aspartate aminotransferase were compared after electrophoretic resolution of its isozymes in polyacrylamide gels. The first one uses L-aspartic acid and Fast Blue BB salt (classical method), the second uses L-cysteine sulfinic acid and a redox system with phenazine methosulfate and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide. The seeds of pea, horse bean and soybean were used as a model plant source of the enzyme. The staining method with L-cysteine sulfinic acid is very reliable and more sensitive than the Fast Blue BB method and allows detection at very low isozyme activities in the gel.