Polyacrylamide gel staining with Fe2+-bathophenanthroline sulfonate☆

Abstract The utilization of Fe 2+ -bathophenanthroline sulfonate for the detection and quantitation of protein bands in cylindrical polyacrylamide gels is described. Two procedures are outlined. The first procedure is used in standard disc electrophoresis and involves fixing the protein with trichloroacetic acid, staining with Fe 2+ -bathophenanthroline sulfonate, and destaining with an ethanol:acetic acid solution. The second protocol reported is utilized with sodium dodecyl sulfate-containing gels. After electrophoresis, the gels are incubated with a methanol: acetic acid solution to remove the sodium dodecyl sulfate. The gels are then stained with Fe 2+ -bathophenanthroline sulfonate and destained with a methanol: acetic acid solution. Excellent background clarity is observed with both methods. Densitometric areas of the stained protein bands are linear to 60 μg of bovine serum albumin, and the limit of detection of this protein is 1 μg. Because of its rapidity of staining and destaining, good sensitivity, and reproducibility of stain intensity, Fe 2+ -bathophenanthroline sulfonate is an excellent protein stain.