SMART™ BCA Protein Assay Kit

SMART™ BCA Protein Assay Kit is a detergent-compatible formulation based on bicinchoninic acid(BCA) for the colorimetric detection and quantitation of total protein. The purple-colored reaction product of this assay is formed by the chelation of two molecules of BCA with one cuprous ion. This water-soluble complex exhibits a strong absorbance at 562 nm that is nearly linear with increasing protein concentrations over a broad working range. (20-2,000 ug/ml) The macromolecular structure of protein, the number of peptide bonds and the presence of four particular amino acids(cystein, cystine, tryptophan and tyrosine)are reported to be responsible for color formation with BCA. Studies with di-, tri- and tetrapeptides suggest that the extent of color formation caused by more than the mere sum of individual colorproducing functional groups. Accordingly, protein concentrations generally are determined and reported with reference to standards of a common protein such as bovine serum albumin (BSA). A series of dilutions of known concentration are prepared from the protein and assayed alongside the unknown(s) before the concentration of each unknown is determined based on the standard curve.