The use method and precautions of cryopreservation

　The cryopreservation tube is also called the strain preservation tube. The commonly used methods for preservation of bacteria in microbiology laboratories include milk method, glycerin method, and inclined plane method. The degree of complexity varies, and the effect varies greatly. At present, most laboratories in China use the experimenters to make their own strain preservation tubes, which not only increases the work intensity, but also due to various conditions, the strain preservation effect is not always satisfactory. Here is a detailed introduction to the use of cryopreservation tubes and precautions.
　　The use of cryopreservation tubes is a science. It is not a simple trilogy of opening the liquid nitrogen tank, putting it in the cryopreservation tube, and closing the liquid nitrogen tank. The scientific and correct use of cryopreservation tubes can avoid the loss of samples and protect the safety of test personnel.

　　How to use the cryotube

　　1. When using cryotubes to store samples, it is strictly required that the cryotubes should be stored in the vapor phase of liquid nitrogen or in the refrigerator. If the cryopreservation tube is stored in a wave of nitrogen liquid, there is a certain probability that the liquid nitrogen will penetrate into the cryopreservation tube during recovery. The liquid nitrogen will cause an imbalance in the pressure inside and outside the tube, which can easily cause the cryopreservation tube to burst and is biohazardous.
　　2. Operate the cryopreservation tube for recovery, and use safety protection equipment throughout the process. It is recommended to wear laboratory clothes, wear cotton gloves and operate on a safe laboratory bench. If possible, please wear goggles or face shield. As the indoor temperature in summer will be higher than in winter, please be extra careful.

　　We should pay attention to the following issues when using

　　1. It needs to be operated in a biological safety cabinet to ensure the sterility of the operation and ensure that the strains are not contaminated.
　　2. Before the inoculation, if the following conditions occur, the cryotube must not be used: the bottle leaks. The cryopreservation protection solution in the cryopreservation tube is turbid (indicating that it has been contaminated). Exceeded the effective storage period.
　　3. When discarding used or partially used cryo-storage tubes, attention should be paid to the prevention of biological hazards.
　　 4. When using cryotubes to store samples, it is strictly required that the cryotubes should be stored in the vapor phase of liquid nitrogen or in the refrigerator. If the cryopreservation tube is stored in liquid nitrogen liquid, there is a certain probability that the liquid nitrogen will penetrate into the cryopreservation tube. During resuscitation, the liquid nitrogenization will cause the pressure imbalance inside and outside the tube, which will easily cause the cryopreservation tube to burst and is biohazardous. .
　　 5. Operate the cryopreservation tube for recovery, and use safety protection equipment throughout the process. It is recommended to wear laboratory clothes, wear cotton gloves and operate on a safe laboratory bench. If possible, please wear goggles or face shield. As the indoor temperature in summer will be higher than in winter, please be extra careful.