After obtaining a sterile environment and sterile materials, we must maintain a sterile state in order to conduct research on a specific known microorganism or use their functions, otherwise various microorganisms from the outside world will easily be mixed in. The phenomenon of the mixing of unrelated microorganisms from the outside world is called contaminating bacteria in microbiology. Prevention of pollution is a very critical technology in microbiology work. On the one hand, thorough sterilization, on the other hand, prevention of contamination, are two aspects of aseptic technology. In addition, we have to prevent the microorganisms under study, especially pathogenic microorganisms or microorganisms that have been genetically engineered that do not exist in nature from escaping from our experimental containers to the external environment. For these purposes, there are many measures in microbiology.
Aseptic room is generally a small room in the microbiology laboratory. It can be constructed from plates and glass. The area should not be too large, about 4-5 square meters, and the height is about 2.5 meters. A buffer room should be set up outside the sterile room, and the door of the buffer room and the door of the sterile room should not face the same direction, so as to prevent bacteria from being carried by the airflow. Both the sterile room and the buffer room must be closed. The indoor ventilation equipment must have an air filter device. The floor and walls in the aseptic room must be flat, not easy to hide dirt and easy to clean. The surface of the workbench should be level. The sterile room and buffer room are equipped with ultraviolet lamps, and the ultraviolet lamp in the sterile room is 1 meter away from the work surface. Workers entering the sterile room should wear sterilized clothing and hats.
At present, most sterile rooms are found in microbiological factories, while general laboratories use ultra-clean benches. The application of ultra-clean benches has made sterile rooms in microbiology laboratories less popular, but large sterile rooms in fermentation plants and other microbiological industries are still very important. The ultra-clean table is a device to prevent pollution that came out in the 1980s. Its main function is to use the air laminar flow device to remove all kinds of tiny dust including microorganisms on the work surface. The electric device allows air to enter the work surface after passing through the high efficiency filter device, so that the work surface is always kept under the control of flowing sterile air. In addition, there is a high-speed air curtain on the side close to the outside to prevent the entry of outside air with bacteria.
Where the conditions are more difficult, a wooden sterile box can also be used instead of the ultra-clean table. The aseptic box has a simple structure and is easy to move. There are two holes on the front of the box, which can be blocked by a small push-pull door when not in operation, and arms can be extended in during operation. The upper part of the front is equipped with glass, which is convenient for internal operation. The inside of the box is equipped with ultraviolet lamps, and utensils and bacteria can be put in from the side door.
It should be pointed out that aseptic operation technology not only plays an important role in microbiology research and application, but also is widely used in many biotechnology. For example, transgenic technology, monoclonal antibody technology, etc.