Previously, three separate, one-dimensional electrophoresis separations have been required to determine the gliadin and high and low molecular weight glutenin subunit compositions of wheat. A method is described here in which only two electrophoresis steps are necessary. After protein extraction with 2-chloroethanol, gliadin composition was determined first by fractionation using polyacrylamide gel electrophoresis at acid pH (A-PAGE). The unreduced polymeric proteins present in the first few millimetres of the A-PAGE gels below the sample wells were then reduced and separated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). These proteins yielded polypeptide patterns that were characteristic of the high and low molecular weight subunits of glutenin. © 1991, Academic Press Limited. All rights reserved.