BCAmääritys

BCA-määritys, also known as the Bicinchoninic Acid Assay, is a biochemical assay used to determine the total protein concentration in a solution. It is a colorimetric assay, meaning it relies on a color change that can be measured spectrophotometrically. The assay works by using bicinchoninic acid to detect cuprous ions (Cu+), which are produced when the protein is reduced by the sample in an alkaline environment.

The BCA-määritys is a two-step process. First, copper ions are reduced by proteins in an alkaline solution, forming cuprous ions. Second, two molecules of bicinchoninic acid chelate with each cuprous ion, forming a purple-colored complex. The intensity of this purple color is directly proportional to the concentration of protein in the sample, and can be quantified using a spectrophotometer at a wavelength of 562 nm.

This assay is known for its sensitivity and tolerance to detergents and other common laboratory reagents, making it suitable for a wide range of protein samples. It is often used for protein quantification in research laboratories, for applications such as Western blotting, enzyme activity assays, and protein purification monitoring. The BCA-määritys typically requires a protein standard, such as bovine serum albumin (BSA), to create a standard curve for accurate quantification. The assay is relatively simple to perform and yields reproducible results.