The operation methods and precautions of common media are as follows
Add water to open the sterilizer lid and add water to the water line. It is best to use the boiled water in the vertical sterilizer to reduce the accumulation of scale in the pot. Pay attention to the water to increase enough to prevent the pan from drying during the sterilization process. After loading and capping the sterilized material, close the sterilizer cover, and evenly tighten the screw on the lid with a diagonal type to make the steam pot tightly closed, so as not to leak air.
The exhaust opens the exhaust port (also called the bleed valve). After heating in an electric furnace, after the water is boiled, the water vapor and the air are discharged together from the vent hole, and when a large amount of steam is discharged, it is maintained for 5 minutes, so that the cold air in the pot is completely drained.
Boost, hold and depressurize When the cold air in the pot is drained, the exhaust valve can be closed and the pressure begins to rise. When the pressure rises to the required pressure, control the voltage to maintain the constant temperature, and start to calculate the sterilization time. After the time reaches the requirement (general culture medium and utensil sterilization control at 121 ° C, 20 min), stop heating and wait for the pressure to drop. When it is close to “0â€, open the bleed valve. Be careful not to vent the air too quickly, otherwise the liquid in the bottle will be flushed out of the container due to the slower pressure drop in the bottle than in the pot.
After sterilized medium, the culture medium is sterilized and placed in a 37 ° C incubator for cultivation. After 24 hours of culture, it can be stored as a sterile medium. After the slant medium is taken out, it is immediately placed into a bevel and then cultured in a blank; semi-solid The medium was placed vertically to form a semi-solid deep agar and then cultured in blank.
Dry heat sterilization is a method of killing microorganisms by using dry hot air called dry heat sterilization. Generally, the articles to be sterilized are packaged and put into an electric oven for baking, that is, heated to 160-170 ° C for 1 to 2 hours.
Dry heat sterilization is commonly used for the sterilization of empty glassware and metalware. Items with rubber, liquid and solid media cannot be sterilized by this method.
Preparation of glassware before sterilization must be properly wrapped and stoppered before sterilization to ensure that the glassware is not contaminated by external bacteria after sterilization. The method of dressing and stoppering commonly used glassware is as follows: the plate is wrapped with paper or placed in a metal flat tube; the triangular bottle is wrapped with thick paper outside the tampon and the bottle mouth, and tied with a cotton rope to prevent the bottle after sterilization. The mouth is contaminated by external bacteria; the pipette is placed at the center of the cotton with a straightened paper clip, gently plunging into the nozzle, the elastic must be moderate, the exposed cotton fiber is uniformly burned through the flame, and the straw is filled during sterilization. Sterilize in the metal tube, or use the paper strip to wrap up from the tip of the straw, gradually roll up, the paper roll at the head end is kneaded and screwed a few times, and then the wrapped straw is concentrated and sterilized.
Sterilize the drying box and put the wrapped items into the drying oven. Be careful not to place them too tightly to avoid obstructing air circulation. Do not allow the utensils to directly contact the inner bottom plate of the oven. Increase the temperature of the oven to 160-170 ° C and keep the temperature constant for 1 ~ 2 h. Be careful not to make the temperature too high. If it exceeds 170 ° C, the paper and cotton wrapped in the utensils will be burnt by burning. If it is to dry the glassware, the temperature is 120 ° C for 30 minutes. Only when the temperature drops to 60-70 °C can the door be opened and the items removed, otherwise the glassware will burst due to sudden cooling.
When sterilizing by this method, never use oil or wax paper to wrap the items.
Flame sterilization is directly sterilized by flame burning, quickly and thoroughly. For the inoculation ring, the inoculation needle or other metal utensils can be directly burned to the red heat on the flame of the Alcohol lamp for sterilization. In addition, during the inoculation process, the test tube or the triangle bottle mouth is also used for sterilization by flame.
As a result, the sterilization methods and sterilization conditions (temperature, pressure, etc.) used for various items were recorded.
The process and precautions for autoclaving are described.
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