Rough separation and fine separation of protein purification

The separation and purification of proteins is widely used in biochemistry research and application and is an important operational skill. SCG Protein Purification System Company-Saipu Instrument has compiled the crude separation and fine separation content of protein purification for everyone. A typical eukaryotic cell can contain thousands of different proteins, some are very rich and some contain only a few copies. In order to study a certain protein, it is necessary to first purify the protein from other proteins and non-protein molecules.

Coarse separation

When the protein extract (sometimes mixed with nucleic acids, polysaccharides, etc.) is obtained, a set of appropriate methods is selected to separate the desired protein from other impurities. Generally, this step of separation uses methods such as salting out, isoelectric point accumulation and organic solvent fractionation. These methods are characterized by simplicity and large processing capacity, which can remove many impurities and concentrate the protein solution. Some protein extracts are large in volume and are not suitable for concentration by accumulation or salting out. You can choose ultrafiltration, gel filtration, freezing vacuum drying or other methods for concentration.

Fine separation

After the rough fractionation of the sample, the volume is generally small, and most of the impurities have been removed. For further purification, chromatography methods generally include gel filtration, ion exchange chromatography, adsorption chromatography, and affinity chromatography. If necessary, you can also choose electrophoresis, including zone electrophoresis, isoelectric point set, etc. as the final purification process. The method used for subdivision level separation is generally small in planning, but with high resolution.

Crystallization is the final process of protein separation and purification. Although the crystallization process does not ensure that the protein must be uniform, it is only when a certain protein has an advantage in the solution to form a crystal. The crystallization process itself is accompanied by a certain degree of purification, and recrystallization can remove a small amount of adulterated protein. Since denatured protein has never been found during the crystallization process, protein crystallization is not only a sign of purity, but also a powerful guideline to determine that the product is in its natural state.