There are two ways to store cells at low temperature, liquid nitrogen tank for short-term storage, and Biobank Freezers for long-term storage.
For a long time, some users have been skeptical about Biobank Freezers, and the focus of skepticism is temperature. They are worried that the temperature fluctuation of Biobank Freezers gas phase mode will affect the samples, and they are also afraid that the temperature will not meet the requirements for cell cryopreservation.
The experimental result is of course: it can be achieved!
Unlike liquid nitrogen tanks, which have a fixed -196°C, Biobank Freezers have a temperature gradient with an upper limit of -150°C.
The US Pharmacopoeia stipulates that in the gas phase liquid nitrogen tank, the temperature of clinical materials should not be higher than -150℃, and the temperature of non-clinical specimens should not be higher than -130℃.
Biobank Freezers uses liquid nitrogen as a cold source to store samples on top of liquid nitrogen. Although the gas phase temperature is very close to -196°C, and the closer the cell storage location is to the liquid nitrogen, the lower the temperature, and the temperature of the tank farthest from the liquid nitrogen can be to -185°C.
Such a temperature design fully complies with the requirements of the US Pharmacopoeia for cell cryopreservation.