Methods for Determining Protein Purity
Proteins are important biomacromolecules in organisms, and their purity directly affects the quality and efficacy of biological drugs. Therefore, accurately determining the purity of proteins is a critical task in the field of proteomics of biological products. The choice of a suitable method for purity determination is vital, and this article will introduce several common methods.
SDS-PAGE Gel Electrophoresis
SDS-PAGE gel electrophoresis is a commonly used method for determining protein purity. By separating the proteins in the sample into bands according to their molecular weight, qualitative and quantitative analysis can be performed through staining or protein labeling techniques. This method is simple and easy to perform, suitable for routine purity determination and sample pretreatment.
High-Performance Liquid Chromatography (HPLC)
HPLC is a high-resolution separation technique that can be used to determine protein purity. Common methods include reverse-phase HPLC and gel filtration HPLC. Reverse-phase HPLC separates based on differences in protein hydrophilicity, while gel filtration HPLC separates proteins of different sizes through molecular sieve principles. HPLC has the advantages of high resolution and high sensitivity, especially suitable for the purity determination of complex samples.
Size Exclusion Chromatography (SEC)
Size exclusion chromatography is a separation technique based on the size of protein molecules. In SEC, large protein molecules pass through the filler faster, while small protein molecules pass through slower. By measuring the position and area of peaks in the sample, the relative content and purity of the protein can be determined.
Spectrophotometry Methods
Spectrophotometric methods determine the concentration and purity of proteins by measuring their absorbance at specific wavelengths. Ultraviolet-visible spectrophotometry (UV-Vis) is the most commonly used, which can be used to determine protein content and purity. However, for complex samples, other methods may need to be combined for further analysis.
The determination of protein purity is of great significance in the field of proteomics of biological products. Choosing a suitable method for determination is crucial to ensure the quality of research and production of biological drugs. In practical applications, the appropriate method can be selected for protein purity determination based on factors such as the complexity of the sample, the purpose of the analysis, and experimental conditions.
How to order?