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Overcoming Variability in Coomassie Quantitation with Protein Standards

ProteaPrep Coomassie Protein Quantitation Kit is a colorimetric assay kit used to determine total protein concentrations in protein solutions. Although the absorbance of Coomassie blue dye at 595 nm is proportional to the amount of protein bound, it is necessary to establish a correspondence between absorbance values and known amounts of protein. Samples with known protein concentrations can be analyzed to generate a standard curve, which can be used to determine the concentration of unknown samples.

The best standard to use is a purified preparation of the protein being assayed. If an exact protein reference is unavailable, then a standard with similar amino acid composition and availability should yield a color change similar to the protein being assayed. This variability information is helpful for choosing a protein standard to use for quantitation the protein of interest.

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