The BCA protein assay is based on a biuretreaction, which is the reduction of Cu2+ toCu+ by proteins in an alkaline solution withconcentration-dependent detection of themonovalent copper ions. Bicinchoninic acidis a chromogenic reagent that chelates thereduced copper, producing a purple complexwith strong absorbance at 562 nm (Smith1985, Wiechelman 1988). This assay can beused to quantify protein concentration with awide variety of samples and can be performedin minutes.
The Novagen® BCA Protein Assay Kit canbe used to determine protein concentrationin the range of 20-2000 µg/ml in either astandard assay or microassay configuration.Kit components are sufficient to complete500 standard-size reactions (50 µl proteinsample plus 1 ml reagent) or 2500 micro-scalereactions (25 µl protein sample plus 200 µlreagent). A BSA standard (2 mg/ml) is providedfor convenient and reliable preparation ofstandard curves.
This assay is robust and can be performedin the presence of many compounds. Somereagents, including chelating agents, strongacids or bases, and reducing agents, interferewith the reduction and chelating reactions onwhich this assay depends (Brown 1989). TheBCA assay is compatible with the followingNovagen protein extraction and lysis reagents:BugBuster Protein Extraction Reagent,PopCulture Reagent, CytoBuster ProteinExtraction Reagent, Reportasol ExtractionBuffer, and Insect PopCulture Reagent. Optionsfor the removal or dilution of interferingsubstances are described in the kit literature.
The BCA protein assay is a simple and reliable protein quantification method.
•500 mlBCA Solution
•15 ml4% Cupric Sulfate
•3 x 1 mlBSA Standard, 2 mg/ml
Toxicity: Multiple Toxicity Values, refer to MSDS (O)
Smith, P.K., et al. 1985. Anal. Biochem.150, 76.
Kessler, R. J. and Fanestil, D. D. 1986. Anal. Biochem 159, 138.
Wiechelman, K., et al. 1988. Anal. Biochem.175, 231.
Brown, R., et al. 1989. Anal. Biochem.180, 136.
Use of the BCA protein assay is permitted for research purposes only.
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