Pipette operation (a) common mistakes
I used to write "pipette operation" when I wrote "pipette selection" on the Internet, and I was fortunate enough to have been quoted several times. Of course, there are more than one person on the Internet who has written similar stuff. But do users value this issue? Unfortunately, the answer is no. A considerable number of people think that pipettes are very simple instruments, and their operation is very simple. There is no need to talk about it, and there is no need for any training courses. In fact? Good pipette handling habits can be beneficial for extending the life of the pipette, improving the accuracy of pipetting and maintaining the health of the user. The following may be used to build some common operating habits in the laboratory, but also a more serious operating habit. I hope you don't find your own shadow in it.
First, install the tip. In laboratories where the pipette is used frequently, the sound of tapping the tip is often heard one after another, adding a bit of music to the boring lab life. When you look into it, the user is afraid that the tip can't be tightened. After the tip is attached to the pipette, tap it again in the tip box. It is hoped that the impact can be used to ensure the pipetting seal. Sex. Where is this operation wrong? First, under the action of the impact, the tip may be deformed to affect the precision of pipetting; secondly, the part of the pipette sleeve that contacts the tip undergoes multiple strong frictions, which gradually becomes rough and it is difficult to ensure the sealing. In order to achieve a good seal, a greater impact force is required, and a vicious circle begins. Third, the handle of a small-range pipette is relatively thin, and it is likely to become fishing under the impact of constant impact. Hook; Fourth, sometimes the impact force is greater than the force that the pipette falls on the ground, and some of the precision parts in the pipette are at risk of being overwhelmed and strike.
Second, the rate of liquid absorption. It is often seen in the laboratory that in order to "improve efficiency", the user quickly releases the thumb during aspiration, which causes the liquid to quickly rush into the tip. As everyone knows, this forces the liquid to form a turbulent state after entering the tip, so that for small and medium-range pipettes, a vapor mist that is invisible to the naked eye will enter the inside of the pipette, for a large-scale pipette. You will see the liquid flush directly into the inside of the pipette. The end result is contamination or even corrosion of the piston of the pipette, which is prone to cross-contamination of the sample and has an impact on accuracy.
The third liquid absorption angle. In order to facilitate the observation of the condition of the sample in the tip during the pipetting process, many users will keep the pipette at an angle of 45o or even closer to the horizontal angle during the pipetting process. But this is wrong again. First, when removing a sample that approaches or reaches the maximum volume of the tip, the tilting of the pipette at a large angle can easily cause the liquid to slip into the shank of the pipette, thereby contaminating or even corroding the piston of the pipette. It is easy to cause cross-contamination of the sample; secondly, the large-angle tilt of the pipette also increases the contact surface of the outer wall of the tip with the liquid, so that the liquid remaining on the outer wall is more when the tip leaves the liquid surface, and it is easy to When the liquid is drained, the liquid is removed from the tip together with the liquid in the tip, thereby reducing the precision of the pipetting. For the pipettes of the small range (such as 2ul and 10ul), the damage to the precision is likely to be fatal!
Fourth, store. A considerable number of users will put the pipette directly on the test bench after the pipette is used. If it is neat, the pipette may be placed in the drawer. This is actually not good! During the pipetting operation, it is inevitable that liquid will enter the inside of the pipette. In the flat state, these liquids will remain on the piston and other components, and after a long period of time, the piston will contaminate the piston and even corrode the piston.
In the problems listed above, it is often mentioned that the piston is corroded. Someone might say: The piston of the pipette I use is corrosion resistant! But I still have to remind two points: First, except for a few low-end pipettes that use all-plastic parts, most of the pipettes have metal parts in the piston assembly; second, as long as the piston is contaminated, Regardless of the material of the piston, there may be problems with reduced internal airtightness of the pipette and cross-contamination of the sample.
In summary, it is necessary for laboratories to establish and improve the SOP (Standard Operating Procedures) used for pipettes and the management of strict pipette operations.
wire holder is made of high quality 304 stainless steel, It is easier to clean without rust, safe, healthy and durable, Prevent rust or chemicals from contaminating food and damaging health. Suitable for putting the wine glass holder.
China leading manufacturers and suppliers of Wine glass holder,Goblet Holder, and we are specialize in Wine Rack,Hanging Wine Rack, etc.
Goblet Holder
Goblet holder,stainless steel goblet holder,goblet rack,steel wire mug rack,wine glass holder
Shenzhen Lanejoy Technology Co.,LTD , https://www.szbrassnuts.com