Cell culture media can be classified in various ways. The following are common classification situations:

Classification by Source

• Natural Culture Media: These are mainly derived from animal body fluids or extracted from tissues, such as serum, plasma, lymph fluid, chicken embryo extract, etc. Such culture media are rich and complex in nutritional components, containing various nutrients and bioactive factors required for cell growth, proliferation, and differentiation. However, their components are not well-defined, and there may be differences between different batches. Moreover, there is a risk of contamination by microorganisms such as viruses and mycoplasmas.
• Synthetic Culture Media: These are culture media formulated with chemically defined substances through artificial design, such as Minimum Essential Medium (MEM), Dulbecco’s Modified Eagle Medium (DMEM), and Roswell Park Memorial Institute (RPMI) – 1640. Their advantages include well-defined components, good reproducibility, and the ability to adjust the formula according to the needs of different cells. The disadvantage is that they lack some components present in natural culture media, and it may be necessary to add serum or other substances to meet the growth requirements of cells.

Classification by Physical State

• Liquid Culture Media: They are in a liquid state, with uniformly distributed nutrients. This is beneficial for cells to fully contact nutrients and for the diffusion of metabolic products. Cells grow and metabolize relatively quickly in liquid culture media, and it is convenient for various experimental operations, such as cell culture, cell passage, and cell counting. They are widely used in fields such as cell biology research and biopharmaceutical production. However, when cells grow in liquid culture media, they lack a fixed support structure. For some cells that need to adhere to a surface for growth, auxiliary materials such as microcarriers may be required.
• Solid Culture Media: Generally, a certain amount of gelling agent is added to liquid culture media to make them solid. For example, agar, gelatin, etc. are added. They are often used in experiments such as cell cloning and cell immobilization. They can enable cells to grow and reproduce at fixed positions, forming single-cell clones, which is convenient for the separation and screening of cells. However, the diffusion of nutrients and the excretion of cell metabolic products are relatively slow, which may affect the growth rate of cells.
• Semi-solid Culture Media: The content of the gelling agent in them is between that of liquid culture media and solid culture media, and they are in a semi-solid state. They have some characteristics of both liquid and solid culture media and can be used in experiments to observe cell movement, chemotaxis, etc.

Classification by Function

• Basic Culture Media: They contain the basic nutritional components required for cell growth, such as amino acids, vitamins, carbohydrates, inorganic salts, etc., and can meet the basic growth needs of cells. They are the basis for other types of culture media. Common ones include MEM and DMEM, which can serve as the foundation for the culture of various cells. On this basis, other components can be added according to the specific needs of different cells.
• Complete Culture Media: On the basis of basic culture media, various components required for cell growth, such as serum, growth factors, hormones, etc., are added. They can provide comprehensive nutrients and growth conditions for cells, enabling cells to grow, proliferate, and differentiate normally in an in vitro environment. They can be directly used for cell culture experiments without the need to add additional components.
• Serum-free Culture Media: They do not contain animal serum. Instead, various growth factors, hormones, vitamins, amino acids, and other components are added to meet the growth requirements of cells. They can avoid the influence of uncertain factors in serum on cell culture, improve the reproducibility and stability of experiments, and are widely used in fields such as cell biology research and biopharmaceutical production. They are especially suitable for cells with high requirements for cell culture conditions, such as stem cells and hybridoma cells.
• Special Culture Media: These are culture media designed to meet the needs of certain special cells or special experiments. For example, selective culture media used for culturing specific types of microorganisms, induction culture media used for inducing cell differentiation, and screening culture media used for screening specific cells.

Classification by Cell Type

• Mammalian Cell Culture Media: They are specifically designed for culturing mammalian cells. There are various formulas according to different cell types, such as the media used for culturing HeLa cells, Chinese Hamster Ovary (CHO) cells, etc. They contain nutritional components and growth factors suitable for the growth of mammalian cells.
• Plant Cell Culture Media: They are used for the culture of plant cells, such as Murashige and Skoog (MS) medium, Gamborg’s B5 medium, etc. They contain macroelements, trace elements, organic substances, and other nutritional components required for plant growth. Plant hormones and other regulatory substances may also be added to promote the growth, differentiation, and plant regeneration of plant cells.
• Microbial Cell Culture Media: They are used for culturing microorganisms such as bacteria, fungi, and yeasts. The formula is designed according to the nutritional requirements and growth characteristics of microorganisms. For example, Luria-Bertani (LB) medium is often used for the culture of Escherichia coli and other bacteria, and Potato Dextrose Agar (PDA) medium is often used for the culture of fungi.