The following is a detailed introduction:

The components of cell culture medium generally include water, nutrients, regulatory substances, and other substances. The formula varies according to cell types and culture purposes. The following is a detailed introduction:

Basic Components

• Water
  It is the main component of cell culture medium. Ultra – pure water is generally required to avoid the influence of impurities, ions, microorganisms, etc., in the water on cell growth.
• Nutrients
  • Amino acids: They are the basic raw materials for cells to synthesize proteins. Usually, 20 essential amino acids are included, such as L – glutamine. Some cells also require specific non – essential amino acids to grow well.
  • Carbohydrates: They mainly provide energy for cells. Common ones include glucose and galactose. Glucose is the most commonly used carbon source in most cell cultures.
  • Vitamins: They participate in various metabolic processes within cells, such as the B – complex vitamins and vitamin C. They are crucial for cell growth, proliferation, and maintaining normal physiological functions.
  • Inorganic salts: They maintain the osmotic pressure, pH value, and ion balance of cells. Common ones include sodium chloride, potassium chloride, calcium chloride, magnesium sulfate, and sodium dihydrogen phosphate.
• Regulatory Substances
  • Serum: Usually fetal bovine serum, calf serum, etc. It contains a variety of growth factors, hormones, carrier proteins, etc., which can promote cell growth, proliferation, and attachment. Generally, the addition ratio in the medium is 5% – 20%.
  • Growth factors: Such as epidermal growth factor (EGF), fibroblast growth factor (FGF), etc. They can specifically promote cell growth and differentiation. The types and concentrations of growth factors required vary according to cell types.
  • Hormones: Hormones such as insulin and hydrocortisone can regulate the metabolism and physiological functions of cells. They are essential components in some cell cultures.
  • Buffer system: Commonly used ones include the phosphate buffer system and the HEPES buffer system. They can maintain the pH of the medium within the range required for cell growth. Generally, the suitable pH for animal cell culture is 7.2 – 7.4.
• Other Substances
  • Antibiotics: To prevent microbial contamination during cell culture, antibiotics such as penicillin and streptomycin are often added. However, in some experiments with high – requirements for studying cell physiological functions, antibiotics may not be added to avoid affecting the normal physiological state of cells.
  • Phenol red: It serves as a pH indicator for the medium. When the pH of the medium changes, phenol red shows different colors. Generally, it is yellow in an acidic environment, red in an alkaline environment, and red or orange in a neutral environment.

Examples of Common Formulas

• DMEM Medium
  • High – glucose type: The glucose content is 4.5 g/L, which is suitable for cells with rapid growth and high metabolism, such as tumor cells. Its formula also contains various amino acids, vitamins, inorganic salts, etc., and usually 10% – 20% serum needs to be added.
  • Low – glucose type: The glucose content is 1.0 g/L, which is suitable for some cells with low glucose requirements, such as neuronal cells. Other components are similar to the high – glucose type, but the content of some components may be slightly different.
• RPMI 1640 Medium
  It is widely used for the culture of lymphocytes, leukemia cells, etc. In addition to basic components such as amino acids, vitamins, and inorganic salts, it contains a relatively high – concentration phosphate buffer system, which can maintain the pH environment for cell growth well. Generally, about 10% serum is added.
• MEM Medium
  That is, Minimum Essential Medium, is a basic medium with relatively simple components. It contains the minimum essential nutrients and can be used for the culture of various cells. It is often used as the basic component of other complex media, and different supplementary components and serum can be added according to cell requirements.