Animal cell culture and its technological development in the production of viral vaccines
Vaccine is an automatic immune agent for the prevention of infectious diseases, which is made of pathogenic microorganisms (such as bacteria, viruses, etc.) and their metabolites through artificial virus reduction, inactivation or genetic engineering. According to the different types of infectious disease pathogens it prevents, it can be roughly divided into bacterial vaccines and viral vaccines. Many viral vaccines used in the population now need to be prepared through the process of virus culture, purification, concentration, inactivation or lysis. Because virosomes are a kind of parasitic microorganisms specialized in host cells, their reproduction needs to be carried out in their specific host cells. Therefore, the cultivation of viruses in the production of viral vaccines requires the cultivation of animal cells in which the virosomes can reproduce first.
1 general process of animal cell culture
Animal cell culture refers to the cultivation of live animal cell populations in vitro. At present, many biotechnology fields will use this technology. Especially in the field of medicine, cell culture has a special role and value. For example, many vaccines or genetically engineered drugs are achieved through cell culture in the research and production process. Commonly used instruments and equipment for animal cell culture include aseptic room, ultra clean workbench, low-temperature refrigerator, pH meter, pressure steam sterilizer, electrothermal constant temperature incubator, culture apparatus, CO2 incubator, constant temperature water bath pot, inverted microscope, centrifuge, sterile filter, washing device, cell counting board and electronic cell technology instrument, etc, The cfam cell culture automation equipment of Shenyang GREAT ELITES Intelligent Equipment Co., Ltd. can realize the doubling culture of cells, and the cleanliness can reach GMP class a cleanliness level. It is suitable for enterprises that need a large number of cultured cells. Cell culture can be divided into primary cell culture and subculture cell culture.
1.1 primary cell culture
Primary cell culture is a process in which various tissues of the animal body are taken out of the body, treated with various enzymes (commonly used trypsin), chelating agents (commonly used EDTA) or mechanical methods, dispersed into single cells, and cultured in a suitable medium, so that the cells can survive, grow and reproduce.
However, there are also some defects in primary cell culture, such as potential exogenous factors, failure to check standardization in advance, and large differences between batches due to the influence of donor age and health status. Therefore, using stable passage cells to culture these viruses instead of primary cells has become the future development direction.
1.2 subculture cell culture
In subculture, when the primary culture is successful, with the extension of culture time and the continuous division of cells, contact inhibition occurs due to the contact between cells, and the growth rate slows down or even stops; On the other hand, it will also be harmful to growth or poisoning due to insufficient nutrients and metabolite accumulation. At this time, it is necessary to divide the culture into small parts and inoculate them into another culture vessel (bottle) for culture. This process is called subculture or re culture. For monolayer culture, 80% confluent or newly confluent cells are the ideal subculture stage. Subculture cell culture in vaccine production refers to the process of culturing stable cell lines, taking out the cryopreserved cell lines designated for production, and culturing them after cell resuscitation.