A technique was developed for analysis of basal membrane proteins from rat kidney glomerulus using two-dimensional electrophoresis by O'Farrell. Basal membranes were isolated from the glomerulus by means of detergent treatment. Various procedures of basal membrane solubilization were studied. About 25 protein fractions with molecular mass from 25 kDa to 330 kDa were detected in the basal membrane after single-dimensional electrophoresis in presence of sodium dodecyl-sulfate. Two-dimensional electrophoresis of the basal membrane proteins and staining of gels with silver nitrate enabled to detect approximately 50 polypeptide fractions with molecular mass from 25 kDa up to 250 kDa at pH 5-7.