The role of bovine serum in cell culture

Modern biotechnology, especially in the field of biomedicine, is almost always closely related to cell culture. For example, many of the research and production of genetically engineered drugs or vaccines are achieved through cell culture. Genetically engineered hepatitis B vaccines are mostly based on CHO Cells are used as carriers; the preparation of genetically engineered antibody drugs is also inseparable from cell culture, and the field of cell engineering is even more inseparable from cell culture technology. Bovine serum is a large amount of natural medium used in cell culture, rich in nutrients needed for cell growth, and has important functions. The composition and content of bovine serum usually vary with the sex, age, physiological conditions and nutritional conditions of the blood donor animals.

The role of bovine serum in cell culture are

1. Provide hormones that can promote cell exponential growth, nutrients that are absent or contained in the basal medium, and low-molecular nutrients;
2. Provide binding proteins, which can recognize vitamins, lipids, metal ions and other hormones, etc., and can bind or modulate the activity of the substances they bind;  
3. It is the source of factors required for cell adhesion and spreading growth; 
4. Act as a pH buffer; 
5. Provide protease inhibitors to inactivate the remaining trypsin when the cells are subcultured to protect the cells from damage;  
6. In some cases, binding proteins can combine with toxic metals and heat source substances to play a detoxification role.

Transportation: Frozen transportation on dry ice to ensure that the quality of the serum is not damaged during transportation.

Serum will produce precipitation during storage and thawing. This is because serum contains a large amount of lipoprotein, fibrin, and polypeptide substances. Repeated freezing and thawing will form precipitation. With the extension of storage time, the amount of precipitation will increase. Therefore, when thawing serum, it should be thawed at 4°C first, and then placed at room temperature until the serum is completely thawed to avoid the increase of precipitation. During the thawing process, it should be mixed to make it evenly heated. When adding serum, avoid adding the precipitate to the culture medium, otherwise, the presence of the precipitate will cause a large number of black spots on the cultured cells, or the cell surface will be covered with a layer of oily substance, which will affect the normal growth of the cells. In order to reduce the loss of serum, the precipitated serum can be collected and centrifuged, and the supernatant can be added to the culture medium for use (it is not recommended to remove the precipitate by filtration, because the precipitate will block the filter membrane and cannot be filtered).