Precautions When Using the Pipette

Pipettes are routine tools in the laboratory. During daily use, some methods and precautions have not attracted the attention of users. Hawach combines the experience accumulated in practice over the years and summarizes them for discussion.

1. Set the pipetting volume: from the large range to the small range is the normal adjustment method. When the scale is rotated counterclockwise, it can be adjusted from the small range to the large range. It should be adjusted to exceed the set volume scale and then adjusted back to the set volume. This will ensure the accuracy of the pipette.

2. Assembling the pipette tip: insert the pipette into the tip vertically, rotate it a half turn to the left and right, and tighten it. It is highly undesirable to use a pipette to strike the tip. This long-term operation causes the pipette parts to loosen due to impact, which can cause the knob of the adjustment scale to become stuck.

3. Aspirate and discharge: in vertical aspiration, the tip of the tip is immersed in the liquid surface below 3mm, before the aspiration, the tip is pre-washed in the liquid, slowly sucking slowly, if the amount is small, the tip should be the tip is a reliable container inner wall.

4. The liquid pipette that sucks the liquid should not be laid flat. The liquid in the nozzle tends to contaminate the inside of the gun and may cause the spring of the gun to rust.

5. The pipette should adjust the scale to the maximum after each experiment, and allow the spring to return to the prototype and extend the pipette’s service life.
6. When sucking, release the liquid slowly and smoothly. Never allowing it to loosen suddenly, in case the solution is sucked in too quickly and flushed into the liquid extractor, corroding the plunger and causing a leak.
7. In order to obtain higher accuracy, the sample solution needs to be sucked once before the sample is taken, and then the liquid is officially pipetted. By removing the serum protein solution or organic solvent, a “liquid film” remains on the inner wall of the tip, which results in the discharge of the liquid. It is too small and produces errors.
8. Liquids with large concentrations and viscosity will produce errors. The amount of compensation to eliminate the error can be determined by experiment. The compensation amount can be set by changing the reading of the reading window with the adjustment knob.
9. The weight of the pure water taken by the analytical balance can be weighed and calculated to correct the liquid take-up. The weight of the 1 ml distilled water is 0.9982 g at 20 °C.
10. When setting the range, please note that the rotation to the required range is clear. In the display window, the set range should not be rotated out of the range within the range of the pipette. Otherwise, the mechanism will be stuck and the movement will be damaged. Liquid device.
11. Pipettes are strictly prohibited to absorb liquids with strong volatility and strong corrosiveness (such as concentrated acid, concentrated alkali, organic matter, etc.).
12. It is strictly forbidden to use a pipette to blow the mixed liquid.
13. Do not use a large-scale pipette to remove a small volume of liquid, so as not to affect the accuracy. Also, if you need to remove a larger amount of liquid outside the range, use a pipette.
14. Pipettes without a tip are not allowed to draw liquid directly.
15. Install the tip with a slight twist to compress the tip so that there is no air gap between the tip and the sleeve.
16. Slow suction slow release, control the speed of liquid absorption. Too fast aspiration rate creates backlash and bubbles, resulting in inaccurate pipetting volumes.
17. Update the tip (or change the capacity) to rinse, remove the organic solvent, and preferably rinse 2 to 3 times.
18. When the liquid temperature is different from the room temperature, wash it several times. The pipetting temperature should not exceed 70 °C.
19. Lift the pipette off the surface and pause for about one second to see if any droplets are slowly flowing out.
20. Do not place the pipette flat or upside down when there is liquid in the tip to prevent liquid from flowing into the pipette.
21. When adding a small amount of sample, extend the tip below the liquid level and mix well.
Hawach provides Standard 8/12 Channels Adjustable Pipettes, Electronic Control Digital Pipettes, Advanced Half Autoclave 8/12 Channels Adjustable Pipettes, Advanced Fully Autoclave Single-Channel Fixed Pipettes, Standard Single Channel Fixed Pipettes, Advanced Half Autoclave Single Channel Adjustable Pipettes, and other Pipettes for your choice.