If you use a pipette in your lab, you’ll know that it’s used to precisely measure and transfer small volumes of liquid in experiments that require a high degree of accuracy.
But what you might not know is that your pipette could be failing you right now, silently, without you even realising it.
And because discrepancies in volumes dispensed can negatively impact the results and reproducibility of your experiments, it’s critical to understand why and how they can fail, as well as what to do about it.
How pipettes fail
1) Mechanical failure
Sometimes pipette failure is obvious. You can see it with your nake eye, or you can feel it while in use.
But pipette failure can also be silent… and therefore sinister.
Mechanical action pipettes, unlike the original glass pipette, often contain numerous internal parts. When these internal mechanisms fail, it’s not always obvious to the operator. For instance, a corroded piston or a leaking seal could cause the pipette to deliver incorrectly, without you even knowing — and sometimes by a large degree. And that in turn impacts the validity of your results.
2) Accident or misuse
Any piece of technical equipment is subject to ‘predictable’ failures caused by the normal wear and tear that occur through frequent usage. However, these kinds of failures only make up around 10% of failures, and they’re often preventable through regular maintenance.
The cold, stark reality is that the vast majority of failures are unpredictable – they occur as a result of accidents or misuse. For instance, accidentally drawing liquid into the body of the pipette can cause piston corrosion or premature seal wear. These events cannot simply be averted by your 12 month maintenance schedule. In fact, you may not even know about it… until it’s too late.
3) Skill of the operator
There’s another way that pipettes can fail, and it has nothing to do with the equipment itself.
The skill of the pipette operator plays a crucial role in its accuracy. For example, your choice of pipetting technique (e.g., reverse vs forward mode) can cause variability in results. And here’s the scary part: if you don’t realise that your technique is an issue, you may not know that it’s affecting your outcomes.
How to reduce failures
What can be done about these silent failures?
Here are two simple but critical strategies:
- Regular training: Alignment around pipette techniques and best-practice protocols – via ongoing, appropriate training – is essential to ensure validity and reproducibility of results.
- Regular calibration: Training alone isn’t enough. You need to ensure your pipettes are calibrated regularly to validate their performance. Think about it: mechanical action pipettes are precision lab instruments – and should be subject to the same quality control principles as other sensitive instruments. Indeed, the more frequently you calibrate your instruments, the faster you’ll detect malfunctioning equipment.
How often should pipettes be calibrated?
If calibration is essential, how often should you calibrate your pipettes?
While it’s crucial to refer to the regulations and standards applicable in your specific situation, it’s often recommended that pipettes and automated liquid handlers be calibrated every 3 to 6 months.
Ultimately, while preventative maintenance can help to minimise predictable failures, the big message is this: pipette failures like accidents or misuse can happen silently at any time, and at any point within your maintenance interval – even immediately after maintenance. So if the validity and reproducibility of results are important to you, don’t take a risk.
If you need any advice about how often you should calibrate your specific instruments, just get in touch with our expert calibration technicians.