Simple, time-saving dye staining of proteins for sodium dodecyl sulfate-polyacrylamide gel electrophoresis using Coomassie blue

Abstract

A fixation-free and fast protein-staining method for sodium dodecyl sulfate-polyacrylamide gel electrophoresis using Coomassie blue is described. The protocol comprises staining and quick washing steps, which can be completed in 0.5 h. It has a sensitivity of 10 ng, comparable with that of conventional Coomassie Brilliant Blue G staining with phosphoric acid in the staining solution. In addition, the dye stain does not contain any amount of acid and methanol, such as phosphoric acid. Considering the speed, simplicity, and low cost, the dye stain may be of more practical value than other dye-based protein stains in routine proteomic research.

Figure 1. Sensitivity of the described procedure.

Different concentrations of BSA were separated by SDS-PAGE and stained with water-soluble CBBR at boiling temperature for 60 s. Lanes 1–6 represent 10 ng, 100 ng, 500 ng, 1 µg, 5 µg, and 10 µg of BSA.

Figure 2. Gels stained with different staining solutions.

BSA (500 ng) was separated by SDS-PAGE and stained with different acid-soluble CBBR at boiling temperature for 60 s. Added to the water-soluble CBBR staining solution were 0.3% HCl (Lane 1), 0.3% phosphoric acid (Lane 2), and 0.3% acetic acid (Lane 4), respectively.

Figure 3. Gels stained at different time periods.

BSA (500 ng) was separated by SDS-PAGE and stained with water-soluble CBBR solution at boiling temperature for 30 s (Lane 1), 60 s (Lane 2), and 120 s (Lane 3) and at room temperature for 1 h (Lane 4), 6 h (Lane 5), 14 h (Lane 6), and 24 h (Lane 7).

Figure 4. Gel washing with different types of water.

BSA (500 ng) was separated by SDS-PAGE, and the separated gels were washed with different types of water: running water (Lane 1), distilled water (Lane 2), and double-distilled water (Lane 3) and stained with water-soluble CBBR solution at boiling temperature for 60 s.