A staining method to intensify a specific high molecular weight glutenin band and the calculation of the relative protein content of the band with laser densitometer scans

A number of staining procedures were evaluated after sodium dodecyl sulphate (SDS) Polyacrylamide gel (PAGE) electrophoretic runs of different wheat cultivars of the Western Cape. The staining method developed by Neuhoff, Arold, Taube and Ehrhardt, (1988) intensified a specific high molecular weight (HMW)-Glu-1 band in comparison with the other HMW-Glu-1 bands of a cultivar. This HMW-Glu-1 band is a genetic marker for good breadbaking quality. The protein content of this band, which showed a variation in its mobility and with a mass between 113.5 kDa and 103.5 kDa, was calculated by using laser densitometric scannings. This protein content can be expressed as a percentage of the total protein content of the SDS-soluble wheat protein of the specific cultivar and can be used to classify cultivars in different groups which correspond to their bread baking quality. This is, therefore, a fast, reliable and easy way to determine or predict breadbaking quality.