The common nutrients contained in cell culture media are as follows:

I. Amino Acids

1. Essential Amino Acids
   • Cell culture media usually contain a variety of essential amino acids, such as lysine, leucine, isoleucine, etc. These amino acids are indispensable for cell growth and proliferation because cells cannot synthesize them by themselves. For example, lysine participates in protein synthesis and is of great significance for maintaining cell structure and function.
2. Non – essential Amino Acids
   • Although cells can synthesize some non – essential amino acids by themselves, adding them to the culture medium also helps cell growth. For example, alanine can participate in the metabolism of sugars and acids. Providing alanine in the culture medium can reduce the burden of cells’ self – synthesis and promote cell growth.

II. Carbohydrates

1. Glucose
   • Glucose is the most commonly used carbohydrate in cell culture media. Cells can obtain energy from glucose through glycolysis and aerobic respiration. In the culture of rapidly proliferating cells, glucose is consumed quickly and needs to be replenished in a timely manner. For example, when culturing tumor cells, due to their vigorous metabolism, they have a large demand for glucose.
2. Other Sugars
   • In addition to glucose, other sugars such as galactose and fructose are sometimes added. These sugars can regulate the cell’s metabolic pathways to some extent. For example, in the culture of some specific cells, galactose can replace part of the glucose, inducing cells to produce different metabolic adaptations, which is helpful for studying cell metabolic mechanisms.

III. Vitamins

1. Water – soluble Vitamins
   • They include the vitamin B family (such as vitamin B1, B2, B6, B12, etc.) and vitamin C. Vitamin B1 (thiamine) participates in the oxidative decarboxylation of pyruvate in cells and is an important coenzyme in cell energy metabolism. Vitamin C has an antioxidant effect, which can protect cells from oxidative damage and may also participate in the synthesis of extracellular matrix.
2. Fat – soluble Vitamins
   • Vitamins A, D, E, and K also play certain roles in cell culture. Vitamin A affects cell differentiation. In the culture of some epithelial cells, an appropriate amount of vitamin A can promote the normal differentiation of cells. Vitamin D is related to cell calcium metabolism and may play a role in the culture of bone cells, etc.

IV. Inorganic Salts

1. Cations
   • Cations such as sodium ions (Na⁺), potassium ions (K⁺), calcium ions (Ca²⁺), and magnesium ions (Mg²⁺) are crucial in cell culture media. Sodium and potassium ions are mainly used to maintain the osmotic pressure balance and cell membrane potential of cells. For example, in the culture of nerve cells, changes in potassium ion concentration will directly affect the excitability of nerve cells. Calcium ions are important second messengers in cell signal transduction and participate in many physiological activities of cells, such as muscle contraction and neurotransmitter release. Magnesium ions are co – factors of many enzymes and play a catalytic role in intracellular biochemical reactions.
2. Anions
   • Anions such as chloride ions (Cl⁻), phosphate ions (PO₄³⁻), and sulfate ions (SO₄²⁻) are also indispensable. Chloride ions and cations jointly maintain the osmotic pressure balance. Phosphate ions are important components of biological macromolecules such as nucleic acids and phospholipids. Sulfate ions play a role in the modification of some proteins and polysaccharides.