Total Protein Assay (BCA & Bradford)

T-Pro BCA Protein Assay Kit


T-Pro BCA Protein Assay Kitis a detergent-compatible formulation based on bicinchoninic acid for the colorimetric detection and quantitation of total protein. This method was base on the reduction of Cu+2 to Cu+1 by protein in an alkaline medium with the highly sensitive and selective colorimetric detection. The purple-colored reaction product of this assay is formed and exhibits a strong absorbance at 562 nm that is nearly linear with increasing protein concentrations over a broad working range (20-2,000 µg/ml). The reaction occurred in T-Pro BCA Protein Assay Kitis not a true end-point method; that is, the final color continues to develop. However, following incubation, the rate of continued color development is sufficiently slow to allow large numbers of samples to be assayed together. Thus, protein concentrations generally are determined and reported with reference to standards of 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.

T-Pro Bradford  Protein Assay kit (1X)


The T-Pro Bradford Protein Assay Kit is a quick and ready-to-use coomassie-binding, colorimetric method for total protein quantitation in an environment containing up to 1% detergent (1% high protein range, 0.1% low protein range). T-Pro Bradford Protein Assay Kit is an improvement over classical Bradford formulations that cannot tolerate detergent contamination of the protein samples. In addition, the T-Pro Bradford Protein Assay Kit reagent shows excellent linearity for a defined range of protein concentrations and shows significantly less protein-to-protein variation than is observed with other Bradford-type Coomassie formulations. 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. Protein concentrations are estimated by reference to absorbance obtained for a series of standard protein dilutions, which are assayed alongside the samples with unknown protein concentrations.






Bradford Reagent



Standard Protocol: 20-1,000 µg/ml



Prepare 1 part of dye reagent with 4 parts of ddH2O

test tube(sample/reagent)

100 µl / 5 ml (reagent 1X)


10 µl / 200 µl (reagent 1X)

Enhanced protocol: 1-25 µg/ml

test tube(sample/reagent)


800 µl / 200 µl (reagent 5X)



160 µl / 40 µl (reagent 5X)


Incubate for 5 mins at RT


Measure absorbance at 595 nm; color will be stable for 1 hr.