BCA Protein Assay - UV Vis Spectroscopy
Colorimetric Quantitation of the Total Protein Concentration in Biological Samples
This spectroscopy application note shows how a Bicinchoninic Acid (BCA) assay is used as colorimetric detection and quantitation of the total protein concentration in biological samples. For more information about this application, proceed to download the page.
How is the BCA Assay Measured?
Bicinchoninic acid (BCA) assay is used as colorimetric detection and quantitation of the total protein concentration in biological samples. The BCA protein assay is compatible with samples that contain up to 5 % detergents (surfactants). Furthermore, simple execution, relatively stable color complexes and the adjustment of the temperature allowing variable sensitivity are advantages of this protein assay.
The first step of the reaction leads to reduction of Cu2+ ions to Cu1+ ions by peptide bonds in alkaline solution. The amount of reduced Cu2+ is proportional to the amount of protein present in the solution. Secondly, two molecules of BCA with one cuprous cation (Cu1+) form a chelation, due to which a purple color is developed. Bovine Serum Albumin (BSA) is used as protein standard and measurements are executed at 562 nm.
For this application has been used a UV7 Spectrophotometer and a CuvetteChanger from METTLER TOLEDO.
