1 · Conventional method: cold storage tube placed at 4 ℃ 10 minutes ---> -20 ℃ 30 minutes ---> 80 ℃ 16 ~ 18 hours (or overnight) ---> liquid nitrogen tank vaporphase long-term storage. -20 ℃ can not exceed 1 hour, in order to prevent excessive intracellular ice, resulting in a large number of peptone cells died, you can skip this step directly into the -80 ℃ refrigerator, but the survival rate slightly lower.
2. Program cooling: the use of the program has been set at a constant temperature cooling machine at -1 ~ -3 ℃ / min speed from room temperature down to (-80 ℃ below) -120 ℃, then placed in liquid nitrogen tank vaporphase long-term storage. Suitable for the preservation of suspension cells and hybridoma.
24-48 hours before freezing, replace half or full medium, so that the cells in exponential growth phase.
Preparation of cryopreservation solution (preparation before use): Another centrifuge tube was added to the medium, serum, dimethylsulfoxide (DMSO) was added dropwise to 20% concentration, which made double the frozen solution, placed Stand-by at room temperature.