Does the cryotube need to be sterile?
The cryopreservation of cells using cryopreservation tubes is one of the main methods of cell preservation. Using cryopreservation technology to store the cells in liquid nitrogen at -196°C at low temperatures can temporarily leave the cells out of the growth state and preserve their cell characteristics, so that the cells can be resuscitated for experiments when needed. In addition, proper preservation of a certain amount of cells can prevent the cells from being lost due to contamination of the cells being cultured or other accidents, which plays a role in cell preservation.
If you just want to extract protein, you can take out the tissue and rinse it repeatedly with sterile saline. There should be no problem.
This provides the following three references:
1. To put fresh tissue specimens into liquid nitrogen, cryopreservation tubes should be used. EP tubes are not well sealed, liquid nitrogen is easy to leak in, and they cannot withstand the low temperature of -198°, and the tubes are easy to burst.
2. Ordinary cryopreservation tubes are fine, no need to specifically remove the enzyme treatment, because the RNase pollution is mainly endogenous, and there is very little outside, mainly from human skin and breathing. It is enough to wear masks and gloves. The effects of cryopreservation tubes are small and negligible.
3. When the tissue is frozen and hardened in liquid nitrogen, it can be stored at -80°, and can be taken at any time without long-term exposure in liquid nitrogen. Of course, we will not store it for a long time. We have never tried to stay in -80° for a year.
But having said that, unless it is a large-scale subject with thousands of specimens, it is generally rarely necessary to preserve specimens for more than one year, right? Dozens of 100 specimens will be disposed of within two to three months at most half a year, so we For small tasks, liquid nitrogen is placed immediately after the tissue is taken, and then transferred to -80°
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