Bicinchoninic Acid Kit for Protein Determination 

• Simple, sensitive colorimetric assay for proteins
• Two stable reagents are used for the working solution
• Faster and easier than the Lowry protein assay
• Compatible with many detergents both ionic and nonionic
• Less variation between different proteins than the Bradford dye-binding assay
• Adaptable for use in microwell plates

Proteins reduce alkaline Cu(II) to Cu(I) in a concentration-dependent manner. Bicinchoninic acid is a highly specific chromogenic reagent for Cu(I), forming a purple complex with an absorbance maximum at 562 nm. The absorbance is directly proportional to protein concentration. This is an alternative to the Folin-Ciocalteu reagent for protein determination.

sufficient for ~500 assays

2-8°C

Lowry, O.H., et al., Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193, 265-275, (1951) abstract

Brown, R.E., et al., Protein measurement using bicinchoninic acid: elimination of interfering substances. Anal. Biochem. 180, 136-139, (1989) abstract

Smith, P.K., et al., Measurement of protein using bicinchoninic acid. Anal. Biochem. 150, 76-85, (1985) abstract

Wiehelman, K., Braun, R. and Fitzpatrick, J., Investigation of the bicinchoninic acid protein assay: identification of the groups responsible for color formation. Anal. Biochem. 175, 231-237, (1988) abstract

FP0010, FluoroProfile^® Protein Quantification Kit

Bicinchoninic Acid Solution 1 L

4%(w/v) CuSO_{4 ·} 5H₂O Solution 25 mL

Protein Standard Solution 5 × 1 mL