It is liquid nitrogen that can be used to freeze cells, it is liquid nitrogen tanks that can freeze cells for longer!
The only differences between the liquid nitrogen tanks used for cell storage and the liquid nitrogen containers used for animal semen preservation are the type of accessories, the structure and layout are similar, and both have to have tanks before liquid nitrogen to achieve sample storage, and there are standards for liquid nitrogen capacity.
A: The amount of liquid nitrogen needs to be referenced to the number of cells!
The safest and most stable way to preserve cells with liquid nitrogen is to have them completely submerged, i.e. the liquid covers them all!
We know that liquid nitrogen at -196°C freezes all living things instantly and that cells are destroyed by direct contact with liquid nitrogen.
Therefore, cells stored in liquid nitrogen tanks are actually processed into lyophilisation tubes and then into lyophilisation boxes and racks before being placed in liquid nitrogen.
So, the liquid nitrogen in the tank where the cells are stored doesn’t go over the cells, it actually covers the top of the freezing rack!
However, if a small amount of cells is to be contained in an accessory bucket, the liquid nitrogen should be covered at the top of the lyophilization tube!
In short, liquid nitrogen to completely cover the cells!
The exact amount of replenishment depends on the size of the tank you choose to store the cells in and how many cells there are!
