Improving data quality and reproducibility (Part 1): barometric pressure can affect pipetting performance

Feb 29, 2016

barometric pressure on pipettingWith so much recent attention on study reproducibility, this is a good time to revisit the Extreme Pipetting Expeditions article series which illustrates how environmental factors can impact data quality, and thus play a role in experimental replication. In this first of the four-part series, we visit Mt. Washington, the highest peak in New Hampshire’s White Mountains at 6,288 ft. (1917 m), to understand the effects of barometric pressure on pipetting.

In the full article, we compare volume delivery by both fixed-volume and variable-volume pipettes on the summit of Mt. Washington and at sea level. For both types of pipettes, we find that the higher altitude results in under-delivery—as much as 30% for a 2 µL pipette operating at its low volume range. While larger-volume pipettes operating at the upper-end of their volume delivery aren’t quite so dramatically affected, even small inaccuracies in liquid delivery, when repeated, can add up to meaningful impacts on your data.

What does this mean for improving data quality and reproducibility?

Volume delivery inaccuracies due to changes in barometric pressure are probably most prevalent when manual pipettes are calibrated offsite, especially if the calibration facility is situated at a different elevation than your lab. With pipette accuracy set at a different lab, you’ll end up pipetting a different volume than intended.

Additionally, you may need to ensure data consistency between different labs—using either automated liquid handlers or manual pipettes—in different geographic areas. Barometric pressure, which certainly varies with elevation, will have an impact on these liquid handling devices.  The resulting inaccuracies can become very important when a different site is trying to repeat your studies.

This factor is especially relevant for drug discovery and preclinical studies laying the foundation for high-stakes drug development programs. Improving data quality at the very beginning of the process can increase the reproducibility of your studies and the likelihood of success—and cost-effectiveness—of the subsequent development programs.

Find out exactly how much of an impact barometric pressure has on pipette performance and subsequent data quality by reading the full article on the Extreme Pipetting Expedition: The effect of barometric pressure on data integrity.


Additional Resources


About the Author

George Rodrigues, Ph.D.

George Rodrigues, Ph.D., is Senior Scientific Manager at Artel, the global leader in liquid delivery quality assurance. Rodrigues is responsible for developing and delivering communications and consulting programs designed to maximize laboratory quality and productivity through science-based management of liquid delivery. Rodrigues is Artel’s chief representative to key commercial clients, government regulatory bodies and industry organizations. His speaking and teaching engagements, along with his publications, build awareness of the challenges and solutions for laboratories in maintaining data integrity and confidence in their testing protocols. He plays a key role in developing the manufacturing and quality assurance processes for Artel products and organizes programs to assist pharmaceutical, biotechnology and clinical laboratories in improving their liquid delivery quality assurance and analytical process control. Rodrigues earned his BS in Chemical Engineering at the U.C. Berkeley, and a PhD in Chemical Engineering at the University of Wisconsin.