What is the principle used to preserve cultures with liquid nitrogen?

The principle of liquid nitrogen preservation of strains.

Strain preservation is to effectively preserve the living microbial community, so that the bacteria are not si, decay and unchanged, so as to facilitate research and application. There are many methods of bacterial preservation, and the principle of preservation is to use the means of drying, low temperature and air isolation to reduce the metabolic speed of microbial strains, so that the life activities of the bacteria are in a semi-permanent dormant state, so as to achieve the purpose of preservation.

The principle of liquid nitrogen ultra-low temperature preservation method is to freeze the cells so that their metabolic activities are stopped, so that the cells can be stored in a dormant state for a long time. In general, the lower the storage temperature, the better the effect. In liquid nitrogen, the temperature can reach -196, so from the perspective of the applicable microbial range, survival period and state stability, the liquid nitrogen ultra-low temperature preservation method is an ideal preservation method.

The survival rate of cultures preserved under -196 was particularly significantly affected by the freezing rate during the cooling process. Generally, antifreeze should be added to the suspension, and the commonly used cryoprotectant is dimethyl sulfoxide.

and glycerin, slow freezing is better.

This method generally preserves bacteria for more than 20 years, in addition to being suitable for the preservation of general microorganisms, some microorganisms that are difficult to preserve by freeze-drying method, such as mycoplasma.

Chlamydia, hydrogen bacteria, molds that are difficult to form spores, bacteriophages.

and animal cells can also be stored for a long time, and the traits do not change. for those in the medium.

Fungi that only produce mycelium, especially the strains in basidiomycetes, must be preserved by this method to obtain satisfactory results. The operation technology of this method is not complicated, as long as there is a liquid nitrogen tank or liquid nitrogen refrigerator equipment, it can be operated.

The principle of preservation is to use the means of drying, low temperature and air isolation to reduce the metabolic rate of microbial strains, so that the life activities of the bacteria are in a semi-permanent dormant state, so as to achieve the purpose of preservation.

The liquid nitrogen ultra-low temperature preservation method is to put the bacteria in an ampoule containing cryoprotectant, and put the ampoule in liquid nitrogen (-196) for preservation. Since the mycelium is at -196, its metabolism decreases to a state of complete cessation. Therefore, there is no need for regular transplantation.

Liquid nitrogen ultra-low temperature preservation method is the most effective and reliable method for long-term preservation of strains (including Agaricus bisporus and Agaricus drumsticks).

When using the strains stored in the liquid nitrogen tank, the ampoule should be placed in 35 40 warm water first, so that the ice cubes in the bottle can be quickly thawed, and then the ampoule should be opened under sterile conditions, and the bacteria should be transferred to the appropriate medium with an inoculation needle, and 22 24 activated culture.