Usually, we may use cryogenic storage tubes to freeze samples in the process of experiments. However, when liquid nitrogen is used for freezing, cryogenic storage tubes often explode, which will not only cause the loss of experimental samples, but also may cause harm to experimental personnel. So how can you avoid this happening?
To figure out how to solve this situation, of course, is to thaw the cause of the explosion of the storage tube.
First of all, cryogenic storage tubes cannot be stored directly in the liquid phase of liquid nitrogen. Because the body and cover materials of common freezing tubes are not the same, the thermal expansion and contraction rates generated during freezing are also different. If the tube is placed directly into the liquid phase, liquid nitrogen may flow into the tube.
In the next recovery of the sample, the cryogenic storage tube was put into a 37℃ water bath, and the liquid nitrogen in the tube was rapidly gasified and expanded, but the gas could not run out of the tube in time, resulting in the explosion of the cryogenic storage tubes.
1. Do not put the cryogenic storage tubes directly into the liquid phase for preservation, but in the gas phase. Or it can be frozen directly in the refrigerator. Remember not to put it directly below the surface of liquid nitrogen.
2. Use an internal rotation cryogenic storage tube. Of course, even the inner freezing tube cannot be directly put into the liquid phase, but the low temperature tolerance of the inner freezing tube is better than the outer screwing cap, which can reduce the possibility of explosion and is relatively safer. The external rotary cryogenic storage tubes are actually designed for mechanical freezing, so it is not suitable for liquid nitrogen storage.
3: What if you really need liquid phase storage? In response to this problem, there are actually specially designed cryogenic storage tubes for this purpose, which can be used to seal the freezing tube and put it into the liquid phase. Of course, it can also be sealed with sealing film, medical tape, etc. In this way, there will be almost no explosion.