Protein Assay Kits

Bradford Protein Assay Kit is a quick and ready-to-use colorimetric assay for total protein quantitation. When coomassie dye binds protein in an acidic medium, an immediate shift in absorption maximum occurs from 465 nm to 595 nm with a concomitant color change from brown to blue. Performing the assay is simple: combine a small amount of protein sample with the assay reagent, mix well, incubate briefly and measure the absorbance at 595 nm. Protein concentrations are estimated by reference to absorbances obtained for a series of standard protein dilutions, which are assayed alongside the unknown samples. Because the color response with coomassie in non-linear with increasing protein concentration, a standard curve must be completed with each assay. Bradford assay is compatible with many of the salts, solvents, buffers, reducing chemicals and chelating agents often used in protein samples. Assays can be performed in tubes, or multi-well plate formats. While the Bradford Reagent is compatible with reducing agents frequently used to stabilize proteins in solution, it is only compatible with low concentrations of detergent. If the protein samples to be assayed have detergents in the buffer, use BCA Protein Assay Kit.

Key Features

• Bradford reagent: stable, ready-to-use kit.

• Colorimetric: measure with a standard spectrophotometer or plate reader (595 nm).

• Easy to use: single reagent; no working reagent preparation required.

• Fast: almost immediate color development; add, mix and read results.

• Broad range: detects protein concentration in the range 1 to 1500 µg/mL.

• Flexible: microplate or cuvette format.