How to Sterilize Glassware by Blast Drying Oven?
Many glassware are often used in the laboratory, such as glass-test-tubes,culture-dishes,beakers, reagent bottles, etc. These glassware need to be sterilized, cleaned and dried after use for further use.
All laboratory utensils and metal lab supplies generally adopts dry heat sterilization, also known as dry hot air sterilization, which is the most used drying sterilization method in the laboratory. The blast drying oven is set at 160 ℃ for 1-2 hours, so that all microorganisms and bacteria can be destroyed in the high temperature environment. During sterilization, the temperature and the setting time should not be too low or too short.
It should be noted that protective measures should be taken when taking out glasswear after sterilization, and gloves should be worn to prevent burns.
The following is the detailed steps:
1. Preparation before disinfection of glassware
Clean and dry all the glassware first. Here, pay attention to the thorough drying. If there are water drops, they will be easy to burst during high-temperature sterilization.
2. Pack the glassware properly:
Packaging can avoid the damage of glassware. Of course, it is recommended to flatten the glassware with flat bottom. It is recommended to use stainless steel shelves with large gaps for glassware that is easy to be broken. If there is no stainless steel shelf and only paper packaging can be used, special attention should be paid to the control of disinfection temperature range.
3. Placement of glasswear
Put the packed Petri dishes, test tubes, pipettes, etc. into the drying oven. They should not be placed too tightly. Generally, they should not exceed 2 / 3 of the volume. Each sterilized glassware should have a gap. When the blast drying oven works, the hot air should be fully circulated.
(the glassware should not be placed on the surface with heating pipe, possibly the bottom, because this surface may be hotter than other surfaces.)
4. Drying oven sterilization
Close the door of the drying oven, turn on the power supply, select 160-170 ℃, and sterilize regularly for 2 hours. At the initial stage of drying and disinfection, the air may contain water vapor, and there may be invisible small water traces on the surface of glassware. At the initial stage of drying, the inside of the drying box is relatively humid. At this time, we can open the back vent to release water vapor for a period of time. After the temperature rises to about 160 ℃ and stabilizes for a period of time, we can close the back vent to fully disinfect the internal glassware.
5. Precautions
If the stainless steel shelf is used for packaging, the user can ignore it. If the paper shelf is used, the temperature should not exceed 170 ℃. If the temperature is higher than the memory, yellowing or even burning, resulting in accidents, our drying box is equipped with an observation window, which can check the internal situation of the box at any time. In case of combustion, the power supply should be turned off immediately, the vent should be closed, and the natural temperature should be reduced to 60 ℃ before treatment. Never open the door of the box to avoid accidents. (cartons are generally not recommended for packaging, but when there is no special shelf, only cartons can be used. Special attention should be paid to safety, and the whole process must be guarded by special personnel.)
6. After disinfection, cut off the power supply, and touch the glassware after natural cooling.