Improvements to the Bradford protein assay

Abstract

The ability to measure protein concentration in solution is widely used in research and the ability to measure the concentrations accurately is of great importance. The measured absorbance of the Bradford assay is slightly linear up to 2000 µg/mL of protein, and linearity is decreased at lower concentrations. An increase in linearity would allow for more accurate estimations of the amount of protein in an unknown solution. This work is investigating the use of alternative alcohols and acids to determine protein concentration in the range up to 20 µg/mL, which demonstrates the most deviations from linearity. Various short-chain alcohols and citric and ascorbic acids will be studied instead of the ethanol and phosphoric acid traditionally used. The results will either reinforce the standard protocol, or introduce an improved method for the preparation of the Bradford reagent.