First, the use of the cell culture process
The general process of cell culture,Including ready, drawing, culture and cryopreservation 4 steps.To conserve cells, especially those not readily available mutant cells or cell lines, cells should be frozen.Cryopreservation temperature is generally -196 ℃ liquid nitrogen temperature, the cells collected in the cryopreservation tube containing protective agent (usually dimethylsulfoxide or glycerol) of the medium, with a cooling rate of the frozen, the final save In liquid nitrogen. At very low temperatures, the time to save the cells is almost limitless.
Currently, 3200 well-identified cell lines (1992) are stocked in liquid nitrogen from the American Standard Cell Bank or Cell Bank (ATCC), including skin fibroblast cell lines from normal and various disease patients and near 75 hybridoma cell lines.
Second, embryo cryopreservation technology
Embryo cryopreservation refers to the use of cryoprotective agents to preserve embryos at low temperatures. This technique was developed in the second half of the 20th century with the application of artificial insemination technology and has become one of the essential means of modern life science research. The principle of cryopreservation of animal embryos is that hypothermia reduces the rate of metamorphic reactions in the embryo. The lower the temperature, the longer the embryo is stored.
At present, a variety of embryo cryopreservation methods have been developed, including slow freezing method, rapid freezing method, one-step freezing method, direct transplantation freezing method and vitrification freezing method. The vitrification method is as follows:
① The embryos were placed in 25% vitrification solution (VS solution) for 15 min at room temperature;
③Preconditioned embryos were stored in high concentration (75% -90%) VS liquid for 20-40min;
③ After two steps cryoprotectant embryos directly into liquid nitrogen preservation
In addition, you can use liquid nitrogen container to save bacteria, vaccines, bone tissue, sperm and other substances, can achieve very good long-term storage effect.