Lab Bradford Assay and SDSPAGE Western Blot Analysis On a m

Lab: Bradford Assay and SDS-PAGE & Western Blot Analysis

On a molecular level, how does coomassie blue stain proteins?

Solution

Answer:

Coomassie Blue forms strong but non-covalent complexes with proteins, most probably based on a combination of van der Waals forces and electrostatic interactions. Formation of the protein/dye complex stabilises the negatively charged anionic form of the dye producing the blue colour which may then be seen on the membrane or in the gel.