Coomassie Brilliant Blue R-250 by MP Biomedicals is a high grade reagent. This is a triphenylmethane dye used in various staining procedures. The suffix “R” in the name of Coomassie Brilliant Blue R-250 is an abbreviation for Red, since the blue colour of this dye has a slight reddish tint. The dye interacts electrostatically however non-covalently, with the amino and carboxyl groups of proteins. The dye molecules bind to proteins including wool to form a protein-dye complex. The formation of the complex stabilises the negatively charged anionic form of the dye producing the blue colour. It also forms a complex with the anionic detergent sodium dodecyl sulphate (SDS). CAS No. 6104-59-2 Quantity Provided: 25 gm per bottle Molecular Formula: C45H44N3NaO7S2 Molecular Weight: 825.97 Soluble in ethanol Coomassie Brilliant Blue has been widely used in biochemical applications as a stain. It is widely used to stain protein samples after electrophoretic separation in a polyacrylamide gel. On binding to a protein, the negatively charged dye molecule will give an overall negative charge to the protein. This property is used to separate proteins or protein complexes using polyacrylamide gel electrophoresis in a technique called Blue Native PAGE. This dye also has applications in forensics.