The separation and purification of protein is widely used in biochemical research and application, and it is an important operation technology. A typical eukaryotic cell can contain thousands of different protein, some of which are very abundant, and some contain only a few copies. In order to study a protein, we must first purify the protein from other protein and non-protein molecules. Use the similarity of various protein to remove the pollution of non-protein substances, and use the difference of protein to purify the target protein from other protein. Each protein is different in size, shape, charge, hydrophobicity, solubility and biological activity, and these differences can be used to extract protein from mixtures such as E.coli lysate to obtain recombinant proteins.
The purification of protein can be roughly divided into two stages: crude separation stage and refined purification stage. The general purification method of protein is resin method. In the coarse separation stage, the target protein is mainly separated from other cellular components such as DNA and RNA. At this time, due to the large sample volume and miscellaneous components, the resin used is required to have high capacity, high flow rate, large particles and wide particle size distribution.