The Correct Use of the Pipette

The researchers often use a pipette to absorb a small amount of reagents or solutions in the laboratory. The micropipette ( such as Standard 8/12 Channels Adjustable Pipettes, Advanced Half Autoclave 8/12 Channels Adjustable Pipettes, Electronic Control Digital Pipettes) can be used frequently in the steps of dilution, coating, etc. The correct operation can ensure that the experiment is not wrong or the error is small, so the correct use of the micropipette is crucial.

In the research of analytical testing, a pipette is generally used to measure a small amount or a small amount of liquid. The correct use of the pipette and some details. Operation is something that many people will ignore and is described in detail in several aspects.

1. Hold a pipette

Hold the handle with the palm and four fingers, the index finger is close to the front hook structure, and the thumb is placed on the control button.

2. The selection range

After pulling the knob that adjusts the range, turn the knob to the appropriate range, and finally press the knob back to the original position. As shown in the figure, the maximum range of the pipette is 1000 microliters.

When adjusting the range, if you want to adjust from a large volume to a small volume, follow the normal adjustment method, and turn the knob clockwise; but if you want to adjust from a small volume to a large volume.

You can first rotate the scale knob counterclockwise to the scale beyond the range, and then adjust back to the set volume, so as to ensure the highest accuracy of the measurement. During this process, never push the button out of the range, otherwise, it will get stuck in the internal mechanism and damage the pipette.

3. Attach the pipette tips

Align the pipette perpendicular to the opening of the tip so that the pipette and the pipette tips are firmly fixed together to ensure that there are no gaps, or the reagent will leak out.

When putting pipette tips on a pipette, many people will knock a few times on the tip of the gun, which is a mistake because it will cause the inside of the pipette.

Parts (such as springs) become loose due to the instantaneous impact force generated by the tap, and may even cause the scale adjustment knob to become stuck. The correct way is to insert the pipette (vertical) vertically.

In the tip of the gun, a slight force can be used to make it tightly coupled. If it is a multi-channel (such as 8 or 12) pipette, you can align the first line of the pipette with the first one.

The tip of the gun is then inserted obliquely and can be clamped by shaking in the forward and backward directions. The logo of the gun head is slightly over the O-ring, and the connecting part can be seen to form a clear seal.

4. Aspiration liquid

Press the knob of the pipette with your thumb to the middle gear and make half of the head of the pipette into the liquid. Do not press the knob to the end. Otherwise, the volume of the liquid aspirated is not correct. Then gently release the thumb and the liquid is Aspirated.

Before aspirating, you can aspirate the liquid several times to wet the tips (especially when you want to absorb a liquid that is thick or different in density from water)

5. Dispense liquid

A. Advance pipetting method. Press the button to the first stop point with your thumb, then slowly release the button to return to the original point. Then press the button to the first stop to discharge the liquid, pause for a while and continue to press the button to the second stop to discharge residual liquid. Finally, release the button.

B. Reverse pipetting. This method is generally used to transfer highly viscous liquids, biologically active liquids, easily foaming liquids, or a very small amount of liquid. The principle is to first inhale more liquid than the set range, when transferring liquid, it is not necessary to blow out the residual liquid. Press the button first to the second stop and slowly release the button to the origin, then press the button to the first stop point to discharge the liquid with the set range, and keep the hold button at the first stop (don’t press down again).

6. Place the centrifuge tube

Place the centrifuge tubes on the racks after well covered, preferably placed from left to right in order to avoid confusion when picking and placing.

7. Remove the tips

Press the white button on the side of the front end of the pipette tip, the tip will automatically fall off.

8. Recall the maximum range

Return the pipette to the maximum range to reduce damage to the spring inside the pipette. Be careful not to over-twist when rotating the knob of the range, which will also cause damage to the spring.