Bradford assay explained:
- Bradford’s assay is Colorimetric. It’s based on color changes that occur when the protein in the sample interacts with a specific reagent causing color changes that can be measured using a spectrophotometer.
- Bradford solution reagent contains the coomassie blue dye. The cationic (unbound) form is green /red with an absorption maximum at 465 nm. The anionic bound form of the dye, held together by hydrophobic interactions, has an absorption maximum at 595 nm.
- Thus; the increase of absorbance from 465 to 595 nm is directly proportional to the amount (concentration) of protein bound to the dye.