Good pipetting practices: How to pipette properly?

Thursday, 25.11.2021. - 11:00

Although pipetting is a common practice in most laboratories, there is always a risk of error. Omissions during pipetting can be easily prevented by knowing the basics of the good pipetting practice, as well as choosing the right pipette for your needs. Below are the most common pipetting errors and tips for proper pipetting and pipette maintenance.

Pipetting may seem like a simple task, however, with different user techniques and the quality of the pipette itself, your results can oscillate significantly and be compromised. To minimize pipetting errors, we bring you a series of practical tips for optimizing the pipetting process, with which you can improve test results.

How to minimize pipetting errors?

1. Clean and check your pipettes daily

By taking care of the pipette on a daily basis, you minimize the risk of contamination. Otherwise, the risk increases, so it is important to clean the pipette before and after each use.

2. Know proper pipetting techniques

Before each pipetting, it is necessary to make a certain sequence of procedures to ensure proper pipetting:

  • pre-wet the pipette tip
  • hold the pipette vertically when drawing the liquid
  • immerse the tip slightly into the liquid during aspiration
  • hold the pipette 45 degree angle while dispensing
  • touch off the pipette tip on the side wall of the container.

3. Use appropriate pipettes

It is important to use a pipette with the maximum volume closest to the volume you plan to aspirate and dispense. The accuracy of your test will improve if the volume used is close to the nominal volume. For example: if you need to dispense 20 μL, a 200 μL pipette would be less accurate compared to a 20 μL pipette which would be ideal. You can find the right pipette for your application in our Practical guide for choosing pipettes and pipette tips.

4. Use suitable pipette tips

Choose the right pipette tips that fit your pipette perfectly to achieve accurate and reproducible results. Follow the pipette supplier's instructions on the correct pipette tips to ensure a good seal between the pipette tip and tip cone. Leaking or poor fitting tips can cause up to 50% error in the pipetted volume.

5. Adapt the pipette to your environment

It is recommended that you adapt your pipette and all test equipment to the ambient conditions, especially if they are exposed to different temperature conditions. This way there will be fewer environmental variables that affect your results.

6. Take a rest during pipetting

If you often have time-consuming, repetitive pipetting procedures in your work, take a break (if possible). This will not only minimize the risk of work related upper limb disorder, but will also rest the mind, muscles and eyes. Fatigue can often be the cause of deconcentration that leads to mistakes, so the results depend significantly on your workflow. If you are doing research that is time-limited and you cannot rest, remember to maintain proper posture. For greater efficiency, it is recommendable to use ergonomic pipettes that will easily adhere to your hand and be easy to use.

Tips for proper storage and handling of pipettes

1. Use a suitable pipette stand for storage

We recommend using appropriate pipette stands to keep the pipettes in a vertical position and avoid potential contamination.

2. Clean and decontaminate pipettes before use

Cleaning and maintaining the pipette does not have to be complicated. Simply wipe the outside of the pipette with 70% ethanol, especially the end of the shaft.

3. Don't overwind beyond the pipette's volume range

Winding the pipette outside of the pipette’s volume range can damage the pipette. If you accidentally overwind the pipette, check the pipette to see if it needs to be re-calibrated.

4. Calibrate pipettes every 6 to 12 months

Pipettes should be calibrated every 6 to 12 months, depending on the frequency of use and your laboratory needs. We recommend that you to organize an appropriate maintenance schedule and check it with other laboratory staff. You can calibrate the pipettes in our calibration laboratory where we use the latest technology and equipment. To make it easier for you to maintain and calibrate pipettes, we have provided our customers with access to our myScal® software in which you can see the time period of pipette calibration, as well as records of all pipettes.

If you want to learn more about good pipetting practice, pipetting techniques and practical tips for everyday work, feel free to contact us! For all interested users, we have been holding a Pipetting Academy for many years, where you can learn all of the above or supplement your existing knowledge and skills.