The Protein Man's Blog | A Discussion of Protein Research

With so many protein assays to choose from, each with its own advantages and limitations, you have to consider their suitability for the application. In some instances, it can be necessary to utilize more than one type of assay. Here, we discuss how to select the most appropriate protein assay.

Which protein assay should you choose for your experiment – the BCA (Bicinchoninic Acid) protein assay or the Bradford protein assay? Since there is practically not a single protein assay method that is perfectly specific to particular proteins or sensitive to all protein types, your success will ultimately depend on three important factors:

Determination of protein concentration is necessary and widely used in protein biology, molecular biology, and other research applications. The concentration of protein samples have to be estimated before proceeding to isolation, purification, and analysis. Various protein estimation methods have been developed so far. Each method has its own advantages and disadvantages over others. Most of these methods depend on the levels of tryptophan, tyrosine and other aromatic amino acids.

The BCA assay (bicinchoninic acid assay) developed by Paul K. Smith et al. has become one of the most widely used protein assays since its introduction in 1985. The advantages offered by the assay help to explain the popularity and widespread use over other protein assays. The advantages of the BCA include: