The use of strong physical and chemical factors to cause all microorganisms inside and outside any object to lose their ability to grow and reproduce forever is called sterilization. Common methods for sterilization include chemical reagent sterilization, radiation sterilization, dry heat sterilization, moist heat sterilization, and filtration sterilization. Different methods can be used according to different needs. For example, medium sterilization is usually carried out by moist heat sterilization, and air is filtered and sterilized.
1. Chemical reagent sterilization
Including gas fumigation, the use of ethylene oxide or formaldehyde to kill microorganisms. The most commonly used reagent sterilization method is disinfectant spraying method. Common disinfectants include isopropanol (75%), ethanol (75%), sebacaldehyde, and neostigmine. In the daily production work, the surfaces of the clean room walls, ceilings, doors, windows, machinery, instruments, consoles, cars, tables, chairs, etc. are regularly sprayed with disinfectants such as ethanol and neostigmine.
2, radiation sterilization
There are mainly radiation sterilization methods and ultraviolet sterilization methods, such as gamma rays generated from radioactive sources for irradiation. This method is mainly used for radiation-resistant radiation of glass products, magnetic products, metal products, rubber products, plastic products and fiber products. Articles; ultraviolet rays can also be used to kill microorganisms, mainly used in glass products, metal products, rubber products, plastic products and fiber products, etc., and can also be used in facilities, equipment, rooms, and the like. Every production room in our company is equipped with UV lamps, which will be irradiated for more than half an hour before production, and will release ozone at the same time.
3, dry heat sterilization
Contains hot air sterilization and flame burning in the oven, which can be used for metal equipment or cleaning
The glassware is placed in an electric oven and maintained at 150-170 ° C for 1-2 hours to achieve thorough sterilization (including bacterial spores). Burning is one of the most thorough dry heat sterilization methods, just like the quality inspection of our company (Hangzhou Ruikai Stem Cell Biotechnology Co., Ltd.), although the tools used (such as tweezers) and glassware are all hot and humid. Bacteria, but still burn it on an alcohol lamp while operating aseptically before using it.
4, moist heat sterilization
Boiling method: boil at 100 ° C for 5 minutes, but only kill the propagule of general bacteria; autoclaving: pressure steam sterilization is carried out in a special pressure steam sterilizer, used in thermal sterilization One of the most common and reliable methods. The advantage is that the penetrating power is strong, the sterilization effect is reliable, and all microorganisms can be killed. Suitable for sterilization of high temperature and water resistant items.
This method is the best choice for viscous liquids that cannot be sterilized by filtration. The three-dimensional cell culture hydrogel produced by our company is a solid-liquid two-phase freely switchable product. It is more viscous in liquid state. Therefore, it is impossible to filter with a filter membrane. Therefore, the autoclave is sterilized at 121 ° C for 20 minutes. In addition, we recommend our company's sterilizer with automatic drying function, consumables, glassware, etc. It is very convenient to dry directly after sterilization.
5, filtration sterilization
Some materials that require sterilization cannot be heated, such as many vitamin solutions. Therefore, many liquids can be sterilized by filtration. Filtration does not kill microorganisms, but excludes them. The filter membrane is generally made of synthetic fiber materials such as cellulose acetate, nitrocellulose, polypolycarbonate, and polyvinylidene fluoride. The pore size of the membrane is generally 0.22 μm, which is mainly used for gas, water, and soluble and unstable substances. Medium, test liquid and liquid medicine, etc.