Pipette Operation Method

Hawach pipette (such as Standard Single Channel Fixed Pipettes, Advanced Half Autoclave Single Channel Adjustable Pipettes) is a measuring instrument used to accurately remove a certain volume of solution. The pipette is only used to measure the volume of the solution it emits. It is a slender glass tube with a large expansion in the middle. The lower end is a pointed mouth, and the upper neck is inscribed with a marking line, which is a mark of the exact volume removed. Therefore, we must pay attention to whether the operation method is correct. The following are the specific methods of operation:

Carefully remove the pipette and put it into the receiving container (in this process, the liquid in the pipe should not leak out). Make the tip of the pipette lean against the inner wall of the receiving container, keep the pipette vertical, and accept the inclination of the container, lift the index finger of the right hand, let the liquid flow freely, and wait about 15 seconds to remove the pipette. Note that a small amount of liquid remaining at the tip can not be blown out by external force (except for the word “blowing” on the pipette).

Proper pipette operation is essential to ensure accurate and reproducible liquid transfers in the laboratory. Follow these general steps for pipette operation:

1. Preparing the Pipette:

  • Ensure that the pipette is clean and free from any residue.
  • Check that the pipette is properly calibrated, and the volume setting matches your intended transfer volume.
  • Ensure that you’re using the appropriate tips for the pipette.

2. Aspirating the Sample:

  • Attach a disposable pipette tip securely to the pipette.
  • Depress the plunger to the first stop (the first stop is used for aspiration).
  • Immerse the tip into the liquid sample.
  • Slowly release the plunger to aspirate the desired volume. Avoid rapid release, as it can introduce air bubbles.

3. Dispensing the Sample:

  • Ensure the tip is positioned correctly in the receiving vessel or container.
  • Depress the plunger to the second stop (the second stop is used for dispensing).
  • Hold the plunger at the second stop for a brief moment to ensure complete and accurate dispensing.
  • Remove the tip from the receiving vessel.

4. Ejecting the Tip:

  • Use the pipette’s tip ejection mechanism to remove the used tip. Some pipettes have manual ejection buttons, while others have electronic ejection.

5. Preventing Cross-Contamination:

  • Use a new pipette tip for each sample to prevent cross-contamination.
  • If you’re working with critical samples, consider using filtered tips to prevent aerosol contamination.

6. Pipetting Techniques:

  • Hold the pipette with a relaxed grip, using your index finger for the plunger and your thumb and middle finger to support the handle.
  • Keep the pipette vertical when aspirating and dispensing to ensure accurate volume transfer.
  • Slowly release the plunger to avoid creating air bubbles or splashing.

7. Calibration and Maintenance:

  • Regularly calibrate the pipette according to the manufacturer’s recommendations or a defined calibration schedule.
  • Clean and maintain the pipette as described in the pipette maintenance guidelines.

8. Training and Documentation:

  • Train laboratory personnel on proper pipetting techniques.
  • Keep a record of pipette calibration, maintenance, and any deviations.

9. Troubleshooting:

  • If you encounter issues like air bubbles, leaks, or inaccurate transfers, troubleshoot the problem before continuing with your work.

Always refer to the manufacturer’s instructions specific to your pipette model, as operation steps may vary. Practice good laboratory pipetting techniques, and handle the pipette with care to ensure accurate and reliable results in your experiments.