Liquid nitrogen is generally needed in chemical plants, gas market, hospitals, beauty parlors, animal husbandry stations, gas stations can be bought.

Liquid nitrogen is dangerous goods, must use liquid nitrogen special storage tank liquid nitrogen tank.

Because it is odorless, colorless, tasteless and non-irritating, nitrogen has no warning characteristics. Humans have no faculties capable of detecting the presence of nitrogen. Although nitrogen is non-toxic and largely inactive, by displacing oxygen in the air and dropping it below the level necessary to sustain life, it can become a simple asphyxiant. Excessive inhalation of nitrogen can cause dizziness, nausea, vomiting, unconsciousness and death.

Death can result from poor judgment, mental confusion, or unconsciousness that prevents self-help. At low oxygen concentrations, unconsciousness and death can occur within seconds and without warning. No one, including rescuers, should enter an area with an oxygen concentration of less than 19.5 percent unless a self-contained breathing apparatus (SCBA) or air tube respirator is available.

Liquid nitrogen container purchase selection knowledge:

First of all, we must look at the amount of specimens, the amount of frozen specimens will determine the size of the volume of the liquid nitrogen container, less specimens to choose a small volume of liquid nitrogen containers, frozen specimen volume of the size of the same decision to buy the size of the liquid nitrogen containers, specimen volume should be selected to choose the volume of liquid nitrogen containers larger. There is also the size of the diameter of the specimen for the selection of liquid nitrogen containers is also very critical.

Generally, the caliber of the liquid nitrogen container should be larger than the diameter of the frozen specimen, for example, the diameter of your specimen is 90mm, and you purchased a liquid nitrogen container with a caliber of 80mm, your specimen can not be put in, can not satisfy your use.

And if you need to store frozen tubes, and the storage volume is large. You can choose a large caliber, large volume liquid nitrogen container to store, large caliber, large volume liquid nitrogen container can be placed inside the drawer type stainless steel freezing rack, is transferred to the storage of 2mm freezing tube design.

Specimen volume: liquid nitrogen preservation. Storage days longer can choose volume 30 liters or 35 liters of 50mm caliber liquid nitrogen container to store, liquid nitrogen static preservation days are more than half a year.

The size of the frozen specimen volume also determines the size of the purchase of liquid nitrogen containers, specimens with large volume should choose a larger volume of liquid nitrogen containers, such as the purchase of a small volume of liquid nitrogen containers to freeze, the specimen will account for the liquid nitrogen containers to take up the space inside the liquid nitrogen containers, liquid nitrogen containers can only be loaded with a small amount of liquid nitrogen, which reduces the number of days of preservation of liquid nitrogen, may be in the cause of the frozen specimens due to the lack of liquid nitrogen and necrosis. Therefore, the size of the specimen volume is critical to the selection of the size of the liquid nitrogen container.

Diameter of the specimen: Generally, the caliber of the liquid nitrogen container should be larger than the diameter of the frozen specimen, for example, the diameter of your specimen is 90mm, and you purchased a liquid nitrogen container with a caliber of 80mm, your specimen can not be put in, and it can not satisfy your use.

Precautions:

1, liquid nitrogen tank in the filling of liquid nitrogen before, to check the shell has no depression, the vacuum exhaust port is intact. If it is touched, the vacuum will be reduced, and in serious cases, the air inlet can not be insulated, so that the upper part of the tank will be frosted, and the loss of liquid nitrogen is large, losing the value of continued use.

2, fill the liquid nitrogen should be careful: for the new tank or in a dry state of the tank must be filled slowly and pre-cooling to prevent cooling too quickly damage to the liner, reducing the service life. You should also pay attention to the method when filling. When filling liquid nitrogen, do not pour liquid nitrogen on the vacuum exhaust port, so as not to cause the vacuum degree to drop. The cover plug is made of adiabatic material, which can prevent the evaporation of liquid nitrogen and also play a role in fixing the cylinder, so the switch should minimize the wear and tear to extend the service life. It is also then indirectly reduce the cost incurred.

3, liquid nitrogen tank inspection is completed after the liquid nitrogen tank storage liquid into the medium, please be sure to close the inlet / outlet valve and booster valve, must open the venting valve. Avoid future explosions and danger.

4, liquid nitrogen tanks containing liquid nitrogen transportation is also very important, but also has a dangerous, so it should also cause us attention. Liquid nitrogen tank transportation of liquid nitrogen media, be sure to ensure that the switching state of each valve should be the same as the storage, and please will be the base of the box pad in the container under the seat circle, the liquid nitrogen tank with a rope will be reliably fixed in the car, so that the liquid nitrogen tank in the process of transportation will not be shaken, so that there is a safer guarantee.

5, the use of the process should be frequently checked. You can observe with your eyes and touch the shell with your hands, if you find the exterior frost, you should stop using it; especially when the inner wall of the neck tube is frosted with ice, you should not use a knife to scrape it to prevent the inner wall of the neck tube from being damaged, resulting in poor vacuum, but you should take out the liquid nitrogen and let it melt naturally.

Expanded information:

Liquid nitrogen preservation, the main use of microorganisms in the -130 ° C below the low temperature of the metabolism tends to stop under the principle of liquid nitrogen (-196 ° C under the ultra-low temperature) to effectively carry out bacterial preservation of the method. This method is easy to operate, high efficiency, the preservation period can generally reach more than 15 years, is currently recognized as one of the strains of long-term preservation technology, and is applicable to all types of microbial strains of bacteria preservation. However, the use of liquid nitrogen preservation, the need to purchase ultra-low temperature liquid nitrogen equipment, and liquid nitrogen consumption, high cost.

Liquid nitrogen cryopreservation of protective agent, generally choose glycerol, dimethyl sulfoxide, dextrin, serum protein, polyethylene azetidine ring, tween 80, etc., the most commonly used is glycerol (10%?20%), different microorganisms should choose a different protective agent, the concentration of the protective agent should be controlled in the microorganisms that do not cause the death of appropriate.

Reference:

Baidu Encyclopedia-Liquid Nitrogen

Reference:

Baidu Encyclopedia-Liquid Nitrogen Preservation Method

Reference:

Baidu Encyclopedia- Liquid Nitrogen