1. Cells: Select the logarithmic growth phase cells and collect cells for 24 hours before changing the fluid.
2. Count: the cells in the conventional method of cell suspension, count, so that the cell density of 5 × 106 / ml, centrifugal to the supernatant, inhalation centrifuge tube.
3. Frozen liquid: first with the culture solution 9 points + DMSO 1 min (or glycerol) dubbed 10% of the DMSO cryopreservation solution, according to the law by drop into the centrifuge tube, and then gently blow the cells with a straw to resuspend the cell.
4. Packing: sub-installed into the sterile ampoules, every 1.5 ml of cell suspension.
5. Sealing: When the plastic is tightened, the bottle can be tightened. If the flame is closed, it will be carefully checked and sealed. If necessary, it can be immersed in the blue liquid. For safety reasons, In the small bag, to prevent the liquid nitrogen immersion, the melting of the explosion caused by the explosion of wounding; yarn bag end of the line to the line, the end tie a small card, specify: cell name, frozen date for later search.