Many everyday tools such as bicycle chains and hinges need lubrication from time to time to work properly. Lab supplies such as centrifuges and pipettes need lubrication as well. In centrifuges, lubricant leads to noise reduction, avoidance of imbalance or leaks, and smooth operation. In pipettes, it is important for longevity, precision, and smooth operation. But less is more when it comes to lubricant. How often and how much lubrication of pipettes is necessary?
It is not obvious when a pipette needs lubrication because the lubricant is inside the pipette and cannot be seen unless the device is disassembled. Pipettes don’t start to squeak. The only noticeable change might be an abrasive feeling or jerking when pushing the operation button which could be a first hint to control the lubricant on the pipette’s piston.
Upon delivery, all pipettes (mechanic and electronic) are lubricated properly by the manufacturer. It is also possible to send the pipettes to a service provider regularly for maintenance. The level of lubrication is then checked automatically. The lubricant used for pipettes is a special mixture and can’t be replaced by common grease used in households. Even centrifuge lubricant has a different composition and should not be used for pipettes. Therefore, when re-lubrication is necessary, special pipette grease must be used. Its properties are optimized for use with pipettes and it sticks to the lubrication point without blending. This special lubricant is also resistant to heat-sterilization in an autoclave, so the pipette doesn’t have to be re-lubricated after this procedure.
Re-lubrication is only necessary when cleaning agents such as soap, liquid detergent, or organic solvents have been used and the lubricant was actively removed. After calibration lubrication is not necessary, it does not affect the lubricant. Furthermore, it is important to only use a very small amount of lubricant, almost invisible to the human eye. This thin layer of lubricant should be applied with a fine cotton swab. Another important detail is the spot where to apply the lubricant. Most operating manuals explain where to lubricate the pipette. For our models (Eppendorf Research® plus, Eppendorf Reference® 2 and Eppendorf Xplorer®), when pipettes have a nominal volume greater than 20 µl, lubricate the cylinder in the lower part and for a nominal volume less than 20 µL, lubricate the small piston directly.