Natural culture medium is also called complex medium, which is a natural organic substance that contains unclear or inconsistent chemical composition. The natural culture medium is mainly extracted from animal liquids or separated from animal tissues. The advantage is that the nutrient components are rich and the cultivation effect is good, but the disadvantage is that the components are complex and the source is limited. There are many types of natural culture medium/liquids, including biological fluids (such as serum); tissue infusions (such as embryo infusions); coagulants (such as plasma).
The characteristics and problems of natural culture medium: In the early days of tissue culture technology, natural culture media, such as protein hydrolysate, serum, were used to culture cells in vitro. Its characteristic is that it is rich in nutrients and various cell growth factors, hormones, and its osmotic pressure, pH, etc. are also similar to the internal environment. The problem is that it is a mixture of unclear ingredients and is restricted by its sources and regulations. The production process is complex, with large differences between batches, and is gradually replaced by synthetic media. In actual work, natural media and synthetic media are often used in combination, and the general natural culture medium is incomplete culture medium.
The widely used natural culture medium is serum. In addition, various tissue extracts and collagen substances that promote cell adhesion are also essential for culturing certain special cells.
Bovine serum is a relatively large amount of natural culture medium for cell cultivation. It is rich in nutrients required for cell growth and has important functions. Bovine serum is divided into calf serum, new bovine serum, and fetal bovine serum. Fetal bovine serum should be taken from fetal cattle delivered by caesarean section; new bovine serum is taken from newborn cattle within 24 hours of birth; calf serum is taken from calves 10-30 days old. Obviously, fetal bovine serum is of high quality, because the fetal bovine has not been exposed to the outside world, and the serum contains the least harmful components such as antibodies and complements.