BCAmenetelmä

BCAmenetelmä, often referred to as the BCA method, is a biochemical assay used to determine the total protein concentration in a solution. BCA stands for Bicinchoninic Acid. This assay is based on a two-step reaction. The first step involves the reduction of copper(II) ions to copper(I) ions by proteins in an alkaline environment. This reaction is known as the Biuret reaction. The amount of copper(I) ions produced is directly proportional to the number of peptide bonds present in the protein, and thus, to the protein concentration.

In the second step, two molecules of BCA chelate with one copper(I) ion, forming a purple-colored complex. This complex has a strong absorbance at 562 nm, which can be measured using a spectrophotometer. The intensity of the purple color is directly proportional to the concentration of protein in the sample. A standard curve is typically generated using known concentrations of a protein standard, such as bovine serum albumin (BSA), to quantify the unknown protein concentrations. The BCA assay is known for its sensitivity, tolerance to detergents commonly found in protein samples, and its compatibility with a wide range of protein types. It is a widely used method in molecular biology and biochemistry research for protein quantification.