Direct red 81 and amido black stain proteins in polyacrylamide electrophoresis gels within 10 min

Proteins separated by SDS-polyacrylamide gel electrophoresis can be stained with organic dyes, the most popular being Coomassie brilliant blue R-250. Coomassie R-250 staining of ovalbumin in an SDS-PAGE gel increased linearly from 2.5 to 60 min. Direct red 81 and amido black staining approached saturation in 10 min. Scatchard analysis showed that the number of direct red 81 and amido black ligands bound to ovalbumin was fourfold higher than that of Coomassie R-250. Direct red 81 and amido black stain proteins in an SDS-polyacrylamide electrophoresis gel in 10 min.