How to disinfect and sterilize pipettes
Although the pipette is small, as one of the routine instruments in the laboratory, it still plays a significant role in the accuracy and performance of our experimental results. Therefore, in order to improve our experimental results, we will talk about the performance of the pipette in this article. Disinfection and sterilization treatment. For pipettes, the two concepts of pipette disinfection and sterilization are often confused. In fact, there is a certain difference between the two: disinfection only requires that the live bacteria on the pipette be controlled within a certain range to reach a harmless level; while the sterilization is more stringent, requiring the elimination of all live bacteria . Therefore, the processing requirements for sterilization are higher than those for sterilization.
One, pipette disinfection
There are two ways to disinfect pipettes:
1. Chemical disinfection. To put it simply, wipe the outer surface of the pipette with alcohol, etc., and then dry it. This should be possible for all pipette brands; if there is a pipette that cannot be disinfected by chemical disinfection, it can only prove that the material of the shell is very poor.
2. UV disinfection. It is to irradiate the surface of the pipette with ultraviolet rays to achieve the purpose of disinfection by destroying the DNA structure of the cell. The time of UV disinfection depends on the intensity of radiation and the resistance of bacteria to UV rays. Most brands of pipettes can be sterilized by ultraviolet light, but you still need to confirm with the supplier in advance. Not all pipettes can be sterilized by ultraviolet light.
2. Pipette sterilization
First of all, let’s talk about conventional high temperature and high pressure sterilization
1. If it is a pipette that cannot be sterilized in its entirety, first use a sterilization bag, tin foil or kraft paper to package the parts that need to be sterilized, 121°C, 1bar atmospheric pressure, and 20 minutes; after sterilization, let it dry completely at room temperature After drying, oil the piston before assembling.
2. If it is a pipette that can be sterilized as a whole (such as the German IKA pipette), you can place the whole pipette at 121°C, 1bar atmospheric pressure, and perform high-temperature and high-pressure sterilization for the whole pipe for 20 minutes.
3. If some pipettes cannot be sterilized by high temperature and high pressure, but need to be used for some special operations, such as RNA extraction, etc., if you are worried that the pipette will be contaminated and affect the results of the experiment, then use 75% ethanol to clean the pipette The head of the device.
If it is used to extract RNA, use 75% ethanol without RNase contamination.
Note: A half-sterilized pipette cannot be sterilized as a whole, otherwise the digital part of the reading will be discolored and the reading will be inaccurate.
followed by UV sterilization
The pipette is made of high-quality UV-resistant materials, and the entire pipette can be exposed to ultraviolet radiation for surface disinfection.
3. Removal of DNA contamination on the pipette
Let’s talk about the processing method first:
1. Dilute the 10X storage solution to 1 times the buffer solution, and soak the inner and outer sleeves from the lower part of the pipette at 95°C for 30 minutes.
2. Rinse the sleeve with distilled water.
3. Dry it at 60℃ or dry it completely.
4. Coat the surface of the piston with silicone oil and assemble the parts.