Measurement of protein using bicinchoninic acid

Anal Biochem. 1985 Oct;150(1):76-85. doi: 10.1016/0003-2697(85)90442-7.

Abstract

Bicinchoninic acid, sodium salt, is a stable, water-soluble compound capable of forming an intense purple complex with cuprous ion (Cu1+) in an alkaline environment. This reagent forms the basis of an analytical method capable of monitoring cuprous ion produced in the reaction of protein with alkaline Cu2+ (biuret reaction). The color produced from this reaction is stable and increases in a proportional fashion over a broad range of increasing protein concentrations. When compared to the method of Lowry et al., the results reported here demonstrate a greater tolerance of the bicinchoninate reagent toward such commonly encountered interferences as nonionic detergents and simple buffer salts. The stability of the reagent and resulting chromophore also allows for a simplified, one-step analysis and an enhanced flexibility in protocol selection. This new method maintains the high sensitivity and low protein-to-protein variation associated with the Lowry technique.

MeSH terms

  • Hydrogen-Ion Concentration
  • Indicators and Reagents
  • Proteins / analysis*
  • Quinolines*
  • Solubility
  • Spectrophotometry

Substances

  • Indicators and Reagents
  • Proteins
  • Quinolines
  • bicinchoninic acid