The Kunkel Pearson Schweigert method (KPS) is one of the methods for determining protein concentration in biological samples. It was developed in the 1970s by American biochemist George Kunkel. The method is based on the use of two reagents: biuret dye and copper sulfate solution.
When the biuret reagent interacts with proteins, a colored complex is formed. This complex can be detected using a solution of copper sulfate, which forms a blue color with the complex. The more proteins in the sample, the more complexes are formed and the brighter the blue color becomes.
To perform the analysis, it is necessary to prepare a sample containing proteins. This may be blood serum, plasma, urine or other biological fluids. The sample is then mixed with biuret reagent and copper sulfate solution and left for some time. As a result, a colored complex is formed, the intensity of which is measured using a photometer.
Kunkel Pearson Schweigert method has high accuracy and sensitivity. It can be used to determine the concentration of proteins over a wide range of concentrations, from low values to several thousand mg/ml. Moreover, the method is fast and easy to use.
However, like any other method for determining protein concentration, the KPS method has its limitations. For example, it is not suitable for determining the concentration of certain proteins, such as hemoglobin and myoglobin, which can form complexes with other substances. Also, the method cannot be used to determine the concentration of many proteins in complex biological samples such as tissues and cells.
Overall, the Kunkel-Pearson-Schweigert method is a useful tool for studying proteins in biological samples and can be used in various fields such as medicine, biology and biochemistry.