PART 1 / CO2 incubator disinfection
Microorganisms in carbon dioxide incubators tend to have a certain impact on the results of the culture. Common microbial treatments include physical filtration and sterilization . Let's explore the two approaches.
1.1 Physical filtration circulates the gas in the box through the filter, so that the cleanliness of the gas in the box reaches a certain level (the common UPLA filter is level 1 and the HEPA filter is level 100); the main function is to maintain the cleanliness of the box and ensure the culture. The environment inside the box, but does not kill any microorganisms and viruses. It only filters the microorganisms in the box into the filter. This requires regular replacement of the filter. The incubator with physical filtration is more suitable. A laboratory with good environmental conditions.
1.2 Sterilize to kill or remove all microorganisms (including spores) from the vehicle to achieve sterility. Sterilized items are called "sterile items", and aseptic processing in the incubator means killing so-called microorganisms, viruses, etc., completely avoiding the influence of the environment on the sample, and eliminating cross-contamination between different samples. According to different removal objects and application environment requirements, an effective method is adopted.
1.2.1 Classification of microorganisms
Microorganisms can be classified into the following categories depending on their resistance:
1 Bacterial propagules are easily killed by general disinfectants. Generally, Gram-positive bacteria are more sensitive to disinfectants, and chemical disinfection effects are more obvious. Gram-negative bacilli often have strong resistance, and general chemical disinfection The effect is not obvious, but it is sensitive to heat, and the thermodynamic method is effective.
2 Bacterial spores and fungal spores have thick spore walls and are highly resistant to chemical disinfectants. General chemical disinfection has limited effectiveness on spores; chemical agents with strong disinfecting ability have a certain killing effect on spores, but The concentration, treatment methods, etc. are strictly required; the common method is to use thermodynamic methods.
3 There are many kinds of viruses, different types of viruses have different resistance to the outside world, and the effects of chemical disinfection are different. RNA activity is obviously affected by temperature, and is generally removed by thermodynamic methods.
4 Fungi are generally resistant to the environment. General UV disinfection methods and chemical reagents do not achieve the desired results. Thermodynamic methods are usually used to boil or use autoclave lamps.
1.2.2 Thermodynamic sterilization method
Common thermodynamic sterilization methods in the incubator include dry heat sterilization and moist heat sterilization.
1 dry heat sterilization will heat the inside of the box to above 120 ° C, humidity within 20%, for a certain period of time, through the high temperature to deactivate the protein and nucleic acid denaturation, to achieve the purpose of killing. Some fungal spores are resistant to certain high temperatures due to thick cell wall protection and sterilization is not complete.
2 moist heat sterilization keeps the saturated humidity inside the box at high temperature to achieve thorough sterilization effect.
The main advantages of moist heat sterilization compared to dry heat sterilization are:
1 The bacteria in the moist heat sterilization absorb water, the water content of the protein is increased, the required solidification temperature is lowered, and the coagulation and degeneration are easy;
2 high-temperature steam has a very high penetrating power for protein, thereby accelerating protein denaturation and rapidly dying;
3 steam has latent heat, which can quickly increase the temperature of the bacteria, thereby increasing the sterilization efficiency.
It can be seen that the humidification sterilization of the incubator is a feasible and effective sterilization method, which can completely eliminate microorganisms such as bacteria, fungi, spores and viruses without secondary pollution. It is best to use a high temperature sterilization once a quarter to eliminate potential contamination risks.
PART 2/CO2 incubator maintenance
It is a good way for wise men to avoid disasters and to be the best measure to reduce losses. The daily maintenance of the carbon dioxide incubator is a good recipe. The following aspects can greatly reduce the probability of pollution:
2.1 With the aim of managing safety, staff in the laboratory should understand the importance of their attitudes and human factors to the experimental environment. Regularly calibrate the system, at least once a year. Once the values ​​are fixed, do not adjust them arbitrarily, so as not to affect the fluctuation of temperature, humidity and CO2 concentration in the tank, reduce the sensitivity of the machine, and also affect the cell production status in the incubator.
2.2 Standard operation must be worn in lab coats, put on slippers or wear disposable shoe covers. Disposable gloves must be worn during the experiment. In particular, before opening the incubator, the hands must be sprayed with 75% alcohol before removing the cell culture flask or culture plate from the incubator. After viewing the cell culture flask or culture plate under the microscope, and then putting it back into the incubator, it is also necessary to spray alcohol to disinfect. The two door switches of the incubator should be taken (released) quickly, otherwise it will affect the concentration, temperature and humidity of CO 2 and cause pollution. Remember not to talk to the incubator when you open the door, breathe and even sneeze.
2.3 Clean and remove dust, dirt and organic stains. Dust, dirt and organic matter are the habitats of microorganisms and may affect the action of decontaminants (antibacterial agents, chemical fungicides and disinfectants), which must be cleaned before disinfection and sterilization.
2.4 disinfection antibacterial medical alcohol can play a good role in disinfection, daily use 75% alcohol to wipe the body and inside of the incubator, once a month. 2%~10% copper sulfate solution can be placed inside the incubator, and the copper sulfate solution has certain bactericidal and bacteriostatic effects.
The above is the entire content of this "carbon dioxide incubator disinfection and daily maintenance" small class, the knowledge points have been marked in red, please always open this article to know the new.
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