Best Practices for Pipette Quality Control

In a modern-day laboratory precision is everything – and the more cutting-edge the research, the bigger are the consequences of the smallest of errors. While sophisticated instruments like spectrophotometers or HPLC systems may receive special attention, there is one tool that often gets overlooked despite its critical role: your everyday pipette. 

Despite its simplicity, a pipette classifies as a “precision instrument” and requires proper maintenance, calibration and handling for accurate results.  

So what are the best practices for keeping your pipettes in top shape? 

While there are many practices that can be implemented, calibration is the most routine check-up. Even the most well-designed pipettes can experience wear and tear over time.  

A pipette may appear sturdy, but its internal components (such as seals, pistons and springs) can degrade and corrode if a pipet is stored in a horizontal position while holding liquids. 

Operator technique is also a major influence as simple mistakes – improper tip immersion depth or inconsistent plunger pressure – can lead to significant errors. 

Routine maintenance ensures your instrument continues to aspirate correct volumes and should be typically performed every 3 to 6 months. This will also prevent “silent failures” - issues that are not immediately visible such as a leaking internal seal.

The other key to effective pipette quality control is setting a calibration frequency that ensures high reliability.  But how to do that?

How do we determine calibration frequency?

To set a calibration frequency, we have to rely on a parameter known as "Mean Time Before Failure" or MTBF, which is the average time it takes for pipettes to "fail". A failure is registered when a pipette's performance falls outside laboratory's set conditions or tolerances, and MTBF is calculated as the average of all times a pipette has failed within its test group.

Once known, MTBF helps predict how long a pipette will remain accurate and precise. It helps determine the best calibration frequency along with factors like reliability, quality control, and regulations. It can vary for individual pipettes based on different factors, such as those shown in the image below:

We mentioned other important factors in setting up calibration frequency such as target reliability. It is based off the laboratory's quality standards, and is given as a percentage - for example, a 95% reliability means that 95% of pipettes are working correctly while the remaining 5% are giving inaccurate results. When setting target reliability compliance with regulatory guidelines is important, and factors to consider include the precision of tests, the effect of faulty pipettes on patient outcomes, legal concerns and production decisions.

Once you known your target reliability and MTBF, you can determine calibration frequency using the image below:

The accuracy and precision of pipette delivery directly affects laboratory results. That is why quality control measures for pipettes should be aligned with those used for other precision instruments. Since pipettes can fail unexpectedly and have a higher failure rate than most other laboratory equipment, the key to effective pipette quality control is setting up a calibration frequency that ensures a high reliability rating.

This is why Pipette.com offers its own accredited calibration and repair services that are not limited by brand. With a single quality system and different plans to suit your science, we can keep your pipette program controlled and compliant. Pipettes may be small, but their impact is still immense. By prioritizing routine pipette calibration and maintenance, your laboratory can ensure precise and reliable liquid handling.

After all in science, “every drop counts”.