In recent years, human health and animal products industry have suffered huge losses every year due to influenza virus. Chicken embryo culture is often used in traditional influenza vaccine production, but this production process is vulnerable to microbial contamination, high endotoxin residue and poor emergency response ability to influenza pandemic, so the development of animal cell virus vaccine industry becomes particularly important. MDCK and other cells have the characteristics such as easy culture, rapid proliferation and high infection efficiency of influenza virus, which is one of the important cell lines suitable for influenza virus vaccine production.

    In response to customer requirements, we have established a special test platform and under the guidance of teacher Dong Wang, we have preliminarily established the basic seed bank and production cell bank of MDCK suspension cells. MDCK cells adapted to serum-free suspension culture were domesticated through long-term experiments. And complete the adaptive passage experiment. On this basis, through genetic modification (inserting anti-cell attachment gene and influenza virus receptor gene), The characteristics of cell suspension culture and sensitivity to avian influenza virus were increased, and influenza virus was cultured with it as vector to obtain higher virus titer, which laid a foundation for developing and establishing MDCK single cell serum-free suspension culture system to produce influenza virus vaccine on a large scale.

    MDCK developed by Ful Institute of Biology has been applied to large-scale cell suspension culture production (7L ~ 50L ~ 250L ~ 1000L cell tanks), and has the following characteristics (see Table 1):

1. High cell activity: > 95%

2. High density: > 9 × 10⁶ cells/ml

3. High titer of HA obtained after virus inoculation: > 9log2

4. The titer of HI antibody after immunization for 21 days: > 8log2

5. Cell growth does not depend on a single individual medium, and producers can have many choices