Proper pipette care all comes down to user education and due diligence
Pipette abuse; unfortunately it’s as common in labs as the instruments themselves. However, a few simple maintenance tasks, along with proper calibration are all you need to keep your pipettes at their best.
“We offer pipette training and certification seminars to educate users on proper pipetting technique along with overall care and maintenance of their pipettes,” says Candie Gilman, a training and support specialist at Artel, about the training they offer to labs interested in setting up a pipette calibration program.
She says educating users on proper technique is essential to avoiding pipette neglect.
“The key to a really good pipette calibration program is being proactive,” Gilman says. “A good calibration program will be able to trend a particular pipette’s performance over time. Another thing that’s very useful is being able to establish action limits because the key to being proactive is to be able to know how your pipettes are performing before they actually have a failure.”
Related Article: Planned Pipette Care
Though when to calibrate depends on what the pipette is being used for and how often, Gilman says Artel uses the guidelines for pipette calibration set by the American Society for Testing and Materials. Those recommend quarterly control checks of ten data points, and monthly verification checks of four data points.
Melinda Sheehan, Eppendorf ’s liquid handling product manager, says just knowing whether a pipette has been calibrated or not is crucial in pipette care, along with keeping it clean.
“If you have some students using it, for example, and one of them clogs it up and doesn’t say anything to the lab manager, you can end up with a situation where you have some corrosive solution inside of the pipette corroding it and nobody knows about it,” Sheehan explains. “Over time, that type of corrosion can disrupt your seal and affect your accuracy.”
Sheehan says labs should use the guidelines of whatever body they are accredited by for pipette calibration/ maintenance and recommends users should check their pipettes at least every year to make sure they’re in calibration. As for general maintenance, that all depends on what the lab is doing. For example, Sheehan says in some cell culture or PCR applications, pipettes may need to be cleaned after each use or experiment.
There are many common errors people make when maintaining or calibrating their pipettes, though the main one is simply not doing maintenance at all. Errors most often happen in pipette storage, handling, overall usage, and pipetting technique as there is a lot of variability from user to user, Gilman says.
“You might have false failures if your technique isn’t as good as it can be,” she says. “False failures aren’t something that anyone wants to encounter.”
She adds overly-aggressive tolerance limits, people calibrating their pipette in a different environment from the one the pipette is actually used in or with different tips than the ones normally used on the pipette, are other key mistakes. Sheehan says that some users clean their pipettes with bleach or other corrosive agents but don’t give the pipette a final rinse with deionized water. That means salts crystallize and disrupt the movement of the pistons. Another error she’s seen is users wiping off all the grease on the pipettes’ pistons when cleaning them but not re-greasing the pistons afterward.
“With normal maintenance and cleaning, you shouldn’t have to re-grease the pipettes, but some manufacturers do recommend re-greasing them and of course, if you’re actually physically scraping the grease off of the piston and the seal, you’re going to have to regrease it,” Sheehan says.
To avoid such mistakes, the user’s manual, manufacturer’s customer service department and literature, as well as third-party calibration companies, and companies that provide training, education, and calibration systems—like Artel—are all good resources to consult.
“[Artel has] a very good resource library [with information on] decontaminating the pipette, how to inspect the pipette and so forth,” says Sheehan. “In the end, you really need to go back to the manufacturer’s manual to see how to do those specific things for that particular pipette.”
Be sure to return to our column next month as we share the essentials of maintaining lab balances.
Questions you should ask before signing up for a pipette service/maintenance agreement