A rapid electrophoretic procedure is described for detecting the human red cell glyoxalase I variants (GLO 1, GLO 2-1, and GLO 2) on cellulose acetate gel (cellogel) on which the sites of enzymed activity are visualized as purple bands against white background. The frequency of GLO1 gene in a Dutch population living in and around Leiden was found to be 0.4544.