Pipettes Part 2: Best Practices for Pipette Maintenance

You know it’s important to ensure accurate measurements from your pipettes at your facility, but did you know one of the most critical factors to consider is your own technical skill? Poor technique can easily affect the accuracy of your results.

Over time, improper technique can also affect your health, increasing your risk for injury. With proper technique, you can be confident that your measurements are both accurate and precise.

What Are Best Practices for Ensuring Accuracy?

It’s important to begin by considering three factors:

  1. The density of the liquid, which allows you to determine the amount of liquid to be aspirated
  2. Your geographic altitude, which affects air pressure and sometimes evaporation
  3. Temperature—perhaps the most important factor. If the temperature of the liquid varies from the temperature of your delivery device, you should either increase or decrease the amount of liquid you aspirate.

What Can I Do When Dispensing?

Use the forward-pipetting technique for standard pipetting:

  • Set the volume required.
  • With the pipette held vertically, press the plunger button to the first stop to expel air.
  • Immerse the pipette tip in the liquid and slowly release the plunger button, aspirating the liquid into the pipette. Wait approximately 1 second to make sure you’ve gathered all of the liquid. Remove the pipette from the liquid.
  • Place the pipette at a 10- to 45-degree angle against the inner side of the receptacle, and then press the plunger button to the first stop. After waiting approximately 1 second, press the button to the second stop to fully dispense the liquid.

When adjusting the volume, always initially aspirate more than the desired volume and then adjust down to the desired volume. Avoid aspirating a smaller amount and then increasing the amount incrementally and stopping at the desired volume.

You can also use other techniques, depending on the type of liquid, the volume, and more. These techniques include reverse-pipetting (use with solutions that foam or have high viscosity), repetitive-pipetting (to duplicate use of the same volume), and heterogenous sample techniques (use with blood or serum).

What Other Methods Ensure Accuracy?

You can take several other steps to improve the accuracy of your pipetting methods.

  • Use high-quality tips matched with your pipette system to achieve maximum accuracy.
  • Use filter tips as needed for your solution or compound to prevent liquids and contaminants from entering the pipette.
  • Pre-wet the tip by aspirating and dispensing the liquid a few times before transferring the liquid (this ensures accuracy by reducing evaporation).
  • Reduce the transfer of body heat to the pipette by handling the tool loosely and wearing gloves (body heat alters the temperature of the solution and changes the desired volume aspiration).
  • Immerse the pipette tip below the meniscus of the liquid when aspirating.
  • Store pipettes in an upright position on a stand when not in use.
  • Review the pipette’s user manual to make sure you are using the instrument correctly.

Pipette Calibration
Store your pipettes in an upright position

What Are Best Practices for Preventing Injury?

You must consider ergonomics while pipetting, especially during longer sessions. Without proper technique, your risk of injury increases.

In addition to pain and swelling, other possible injuries include:

  • Tendonitis: causes inflammation around the thumb and fingers and can develop from gripping a pipette too tightly and depressing the plunger with too much force
  • Cubital tunnel syndrome: causes numbness in the fingers and loss of hand strength and can develop from resting the elbow on a hard surface while pipetting

The best way to avoid injury is to use proper ergonomics. Consider taking these steps to help avoid injury:

  • When seated, maintain a 90-degree angle in the body, with your back straight. Support your lower back with the chair and keep your wrist in line with your forearm.
  • Keep an upright posture while standing. Position your forearm so that it is parallel to the floor, and align your wrist with your forearm.
  • Take short breaks (a few minutes) every 20–30 minutes during pipetting sessions.
  • Ensure that both the seat and workstation are appropriately adjusted to your body size to prevent fatigue.
  • Alternate between sitting and standing when possible.

How Can BCC Help?

These methods can help you proactively protect your health while ensuring the accuracy of your results. It is also important to enlist professionals to keep your equipment calibrated. With our calibration services tailored to your unique needs, your lab will be well on its way to efficiently and accurately producing excellent results.

This is a two-part series on pipettes. See Pipette Maintenance Part 1 for information on best practices for pipette maintenance.

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Pipettes Part 2: Best Practices for Pipette Maintenance