8 Tips to Improve Your Pipetting Technique

In a recent blog post, TTE highlighted the quality, convenience, and standard compliance offered by metrology based pipette calibration service providers. Here at TTE, our lab technicians take conscious steps to utilize the best procedural practices, making sure we are compliant with every aspect of FDA regulations and ISO 17025 and ISO 8655 standards. In order to obtain the most accurate results, we practice a number of tried and true pipetting techniques to lower our risk of error.

8 Tips for Improving Your Pipetting Practices

The following is a list of 8 helpful tips for your lab to consider, based on our own successes. These techniques are intended to further improve your pipetting practices and ensure the most accurate test results.

Consider these best practices the next time you pipette:

1. Use consistent force when installing the pipette tip: When installing your pipette tip, it’s important that you apply the same, consistent force to ensure a proper fit each time. Do not jam the tip in place; this can damage your pipette tip and negatively affect your results.

2. Pre-wet the pipette tip: To flush any residual substances from the pipette tip and prevent cross-contamination, be sure to pre-wet the tip by aspirating liquid into the tip once and then dispensing all liquid out. Do two this two to three times before taking the desired volume.

3. Aspirate at 90 degrees, dispense at 45 degrees: The angle at which the pipette aspirates and dispenses a substance is important for test accuracy. These precise angles ensure that the desired measurement enters the tip properly and that all of the liquid fully dispenses without leaving any residue in the tip.

4. When aspirating, place the tip just below the surface: Putting the tip just below the surface of the liquid, approximately 2-3mL, ensures no air is being aspirated and allows you to draw up more than the measured volume. You can then release the excess liquid to get your desired measurement.

5. Release plunger slowly: During the aspiration process it is important to release the plunger with a slow, controlled motion to avoid air bubbles.

6. Dispense against the side of the receptacle: Be sure to dispense against the side of receptacle or into the liquid already in the receptacle. Never shoot or squirt the liquid into the air; doing so can affect your measurement results.

7. Touch off at the very end of your receptacle: When dispensing, ensure all the liquid comes out of the tip and touch off at the very end of the receptacle. Water tension can sometimes prevent all of the liquid from exiting the tip so be sure to pull the residual amount out of the tip.

8. Don’t hold pipette when you’re not pipetting:  Holding a pipette that is not in use affects thermal transfer, which can ultimately effect measurement. There are environmental factors that can affect the state of a pipette, including temperature, altitude, and liquid density, so be cognizant of these factors when pipetting.

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We have found these 8 pipette techniques to be extremely useful in our lab space; they have also added to the high quality standards we seek to execute. If you are not already practicing these techniques, doing so will improve your measurement accuracy and maintain the state of your pipette equipment. Remember, even the most experienced experts can find room for improvement.

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