Steps of using adjustable pipette

Pipette is a small precision equipment commonly used in biochemistry and molecular biology experiments. The pipettes used in general laboratories include continuously adjustable pipettes and discontinuous adjustable pipettes.

The steps of using the adjustable pipette are as follows:

(1) Select a pipette with a suitable range, the volume of the measured liquid cannot be higher or lower than the range of the pipette, otherwise it cannot be accurately measured.

(2) Set the pipetting volume. Most pipettes use an adjustment wheel to set the pipetting volume, and the set volume is displayed on the dial. Note that when adjusting the adjustment wheel, the action should be slow and cannot be quickly rotated to avoid damage to the adjustment system of the shifter.

(3) Select the appropriate pipette tip. The pipette tip and pipette must be matched and installed correctly. Push hard and gently rotate the pipette tip to tighten it. The pipette tip is usually packed in a box and used after sterilization.

(4) Draw liquid. Hold the pipette vertically, and then push the push button to the first dead point, immerse the tip in the liquid, the liquid level does not exceed the tip, then slowly release the push button to absorb the liquid, wait 1 ~ 2s before leaving the liquid surface. The action should be slow when aspiration, to prevent air from being sucked into the pipette tip with liquid, resulting in inaccurate measurement.

(5) Release liquid. The head of the pipette tip leans against the wall of the container at an inclination of about 10 to 20o. Slowly press the push button to the first stop point. After staying for 1 to 2 seconds, press the second stop point to discharge all liquid. Release the push button to return to the original position.

(6) Withdraw the pipette tip. Press the button of unloading the gun head and withdraw the pipette head. The pipette must be removed from the pipette tip before it can be placed on the laboratory table, because any remaining liquid will flow back to the pipette rod when lying flat. Note that the used pipette tips must be placed centrally in glassware, and should not be discarded on the bench or the ground.