Among all in vitro cell cultures, animal cell cultures are the most difficult. The following are the special conditions it needs.

(1) Serum: Serum is often needed for animal cell culture in vitro. The most commonly used is calf serum. Serum provides essential factors for growth, such as hormones, trace elements, minerals and fats. One day people really learned to prepare the same culture solution as serum, and then serum can replace it. Here, serum is equal to the natural nutrient solution of animal cells cultured in vitro.

(2) Support: Most animal cells have the habit of adhering to the wall. Glass and high-speed freezing centrifuge plastic are often used as supports in vitro culture.

(3) Gas exchange: In the process of cell culture, the ratio of carbon dioxide and oxygen should be constantly adjusted to maintain the required gas conditions. It can be imagined how difficult it is to recover the equipment quickly after each unpacking operation, which determines that the equipment for animal cell culture in vitro requires high requirements and large investment.

Special conditions of plant cell culture

(1) illumination: The light conditions of plant cells cultured in vitro are not strict, because the substances needed for cell growth are mainly supplied by the culture medium. However, light is not only related to photosynthesis, but also to cell differentiation. For example, photoperiod can regulate sexual cell differentiation and flowering, so light conditions are particularly important in the early plant cell culture process for the purpose of obtaining plants. The process of obtaining important substances (such as drugs) by in vitro culture of plant cells, most of which are suspended in a reactor.

(2) Hormones: The division and growth of plant cells need the regulation of plant hormones, and auxin to promote growth and mitogen to promote cell division are the most basic hormones. The division, growth, differentiation and individual growth cycle of plant cells are regulated by corresponding hormones. Compared with animal cells, the principle of hormone demand of plant cells in vitro culture has been understood, its application technology has been quite mature, and a set of culture medium has been widely used as a commodity. At the same time, it solves the demand of plant cells for water, nutrition, hormones, osmotic pressure, pH and trace elements.