How does Coomassie blue work?

The process involves immersing the cells in the dye, and any extra stain is removed with a solvent in a process called "destaining." This makes the proteins appear as blue bands against a clear background. When proteins interact with Coomassie blue in an acidic solution, their positive charges prevent the dye from becoming protonated, resulting in a blue color. This binding shifts the dye's absorption peak from 465 nm to 595 nm, and the increase in absorbance at 595 nm is used to measure the presence of proteins.