Among the many uses of liquid nitrogen tanks, only sample storage requires liquid level, especially cell embryos. As long as there is a need for long-term static storage, the issue of liquid level will always be around. Moreover, the more precious the liquid nitrogen tank storage cells are, the more emphasis must be placed on the liquid level.
Because liquid nitrogen is volatile, part of the liquid nitrogen tank installed in the vacuum insulation device will still evaporate naturally, and the total amount of liquid nitrogen will decrease over time. However, if cells are to be preserved stably, they must be completely soaked in liquid nitrogen. Therefore, the liquid level has to be required.
In theory, the higher the better!
In practice, it is limited by the capacity of the container, and some vapor phase space must be considered, usually based on the cell storage height!
It is necessary to ensure that the cells are always soaked in liquid nitrogen. No matter whether the cells in the liquid nitrogen tank are stored on a freezing rack or in a round bucket, or wrapped with cotton thread and put into the bottom of the tank, in short, the liquid nitrogen level must cover the highest point of the cells. .
In this way, the safety of the cells at the top can be ensured. Otherwise, with the natural loss of liquid nitrogen, the liquid level in the liquid nitrogen tank will drop, and the temperature of the uncovered part will rise, and the cell activity may be damaged. If the liquid nitrogen is not replenished until only 1/3 of the liquid nitrogen is left, the top cells will most likely lose activity and the experimental process will be greatly affected.
It is for this reason that the liquid level stored in the cells of the liquid nitrogen tank is required to be based on the height of the cells, instead of replenishing the liquid nitrogen when it reaches 1/3 of the total capacity, as is the case when only liquid nitrogen is stored. Did you know?