How to pipette the pipette

Although the Pipette is small, it is one of the routine instruments in the laboratory, and it plays an important role in the accuracy and accuracy of our experimental results. Therefore, in order to improve our experimental results, Lebe will talk about this in this paper. Disinfection and sterilization of the liquid. For pipettes, the two concepts of pipette sterilization and sterilization are often confused. In fact, there are certain differences between the two: Disinfection only requires that the live bacteria on the pipette be controlled within a certain range to achieve a harmless level; while sterilization is more stringent, requiring the elimination of all live bacteria. Therefore, the sterilization process is required to be higher than the disinfection.

First, pipette disinfection

There are two ways to pipette:
1. Chemical disinfection. Simply put, wipe the outer surface of the pipette with alcohol, etc., and then dry it. This should be possible for all pipette brands; if a pipette cannot be chemically sterilized, it can only prove that the material of the casing 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 cells. The duration of UV disinfection depends on the intensity of the radiation and the resistance of the bacteria to UV light. Most brands of pipettes are UV sterilizable, but they still need to be confirmed with the supplier beforehand. Not all pipettes can be UV sterilized.

Second, pipette sterilization

First of all, let's talk about conventional autoclaving

1. If it is a non-integrated pipette, first pack the parts to be sterilized with sterilized bag, tin foil or kraft paper, 121 ° C, 1 bar atmospheric pressure, 20 minutes; after sterilization, completely dry at room temperature After drying, oil the piston and assemble it.

2. If it is a sterilizable pipette (such as the German IKA pipette), the whole pipette can be placed at 121 ° C, 1 bar atmospheric pressure for 20 minutes of high temperature and high pressure sterilization.

3. If some pipettes can't be autoclaved, but they need to be used for some special operations, such as RNA extraction, if you are worried that the pipette is contaminated and the experiment results, then wash the pipette with 75% ethanol. The head of the device.
If it is used to extract RNA, use 75% ethanol without RNase contamination.

Note: Half-disinfected pipettes are not allowed to be disinfected as a whole. Otherwise, the digital part of the reading will be discolored, and the reading will be inaccurate.

Followed by UV UV irradiation sterilization

The IKA pipettes are made of high-quality materials that are resistant to UV light. The entire pipette can be exposed to UV light for surface disinfection.

Third, the removal of DNA contamination on the pipette

Let us first talk about the processing method:

1. Dilute the 10X stock solution into 1x buffer and soak the inner and outer sleeves of the lower part of the IKA® Alpha or Precision pipettes at 95 °C for 30 minutes.

2. Rinse the sleeve with distilled water.

3. Dry at 60 ° C or dry completely.

4. Apply silicone oil to the surface of the piston and assemble the parts.

Cleaning solution, preparation of 10X stock solution:

30.6g NaCl

39.2g Glycine

523ml H ₂ O

Add 1 N HC1 to 1000ml