The Working Principle of Cell Culture Medium

Cell culture medium is crucial for the in – vitro survival of cells. Its working principle is based on the precise simulation and maintenance of the nutrients and environment required for cell growth.

From the perspective of nutrient supply, cell culture medium contains all kinds of nutrients essential for cell growth. Amino acids, the building blocks of protein synthesis, exist in appropriate proportions in the medium, providing raw materials for cells to construct complex protein structures. For example, arginine is involved in cell proliferation and immune regulation and is indispensable for the normal growth of many cells. Carbohydrates serve as the energy source for cells. Glucose, through a series of metabolic pathways within the cell, such as glycolysis and the tricarboxylic acid cycle, provides ATP to maintain the life activities of the cell.

Vitamins and inorganic salts are equally important. Vitamins play a co – enzyme role in the metabolic processes of cells. For instance, vitamin B12 is involved in the nucleic acid synthesis of cells. Inorganic salts maintain the osmotic pressure balance inside and outside the cell. For example, sodium and chloride ions regulate the water influx and efflux of cells, ensuring the stability of cell morphology and function.

In terms of environmental maintenance, the buffer system of the medium is the key. Take the commonly used phosphate buffer system as an example. It can effectively resist the impact of external factors on the pH value of the medium. When acidic substances are produced by cell metabolism, the alkaline components in the buffer system react with them, and vice versa. This ensures that the pH value of the medium remains stable within the range suitable for cell growth, generally 7.2 – 7.4 for animal cells.

In addition, serum plays multiple roles in cell culture medium. Serum is rich in growth factors, hormones, and carrier proteins. Growth factors, such as epidermal growth factor, can bind to receptors on the cell surface, activating the signal transduction pathway inside the cell and promoting cell proliferation and differentiation. Hormones regulate the metabolic activities of cells. For example, insulin can promote the uptake and utilization of glucose by cells. Carrier proteins can carry some poorly soluble nutrients, making them more easily absorbed by cells.

Cell culture medium provides comprehensive nutrients, a stable environment, and various regulatory factors, creating conditions for the growth, proliferation, and maintenance of normal physiological functions of cells in vitro. It is the foundation for the success of cell culture technology.