How to Choose Between Electronic and Mechanical Pipettes?
Are you looking for a pipette for sterile work, one you can quickly sterilize when needed? Do you pipette a lot and seek a light and ergonomic solution? Or perhaps you need a pipette to speed up your work?
Both mechanical and electronic pipettes have their place in a lab.
Both electronic and mechanical pipettes have their advantages and considering in which kind of work a pipette will be used should be done prior purchasing one. Mechanical pipettes shine with how easy they are to sterilize, and electronic pipettes can speed up work and reduce variance.
An electronic pipette can significantly speed up work, especially when working with micro-well plates or high number of samples. As an example, an electronic multichannel pipette can fill in 96 well plate 4 times faster compared to mechanical multichannel pipette.
The time savings are largely thanks to pipetting modes that enable repetitive pipetting, without the need for aspirating liquid in between steps. For example, multi-dispensing mode can be used to pipette master mix or reagent to all wells or tubes in one go. And in spectrometric or colorimetric assays and immunoassays sequential dispensing mode can be used to pipette standard curves and calibration curves. When planned smartly, you can save time and pipette tips. Remember to consider cross-contamination and pipette in the correct order.
If the number of samples is moderate, and you can’t use repetitive pipetting modes, there is no huge difference in speed if you use an electronic one or mechanical one.
An electronic pipette can help reduce variance in pipetting, and especially between the users.
A test was conducted with three distinct groups of testers: experts, moderately experienced, and people with no prior pipetting experience. All testers performed a set of pipetting tasks using mechanical and electronic pipettes.
For mechanical pipettes, the more experienced the pipette user is, the more accurate and precise are the results, especially in small volumes. A good pipetting technique with even piston movement will ensure good results with mechanical pipettes.
For electronic pipettes there is only a small difference in accuracy and precision between the testers. The user influence is eliminated because the motor is operating the piston always the same way regardless of the user experience.
There are two very different reasons for being interested in pipetting ergonomics. Firstly, pipette and pipetting ergonomics affects the quality of the pipetting results. Secondly, even though pipettes have become lighter than ever, pipetting is still repetitive work that requires a considerable amount of muscle activity. Such work can result in repetitive strain injury.
Modern electronic pipettes are very close to mechanical ones in terms of size and weight, and the shape of the handle and overall balance of the instrument can be excellent in both options. The main differences between electronic and mechanical pipettes in terms of ergonomics is that an electronic pipette will move the piston and eject the tip with a click of a button, whereas with a mechanical pipette the user manually controls the actions with their thumb.
Often tip ejection is the heaviest part of pipetting, especially when working with multichannel pipettes. A good mechanical pipette is light to use, and even the tip ejection can be relatively light. But they will not match clicking a button with an electronic pipette.
Cleaning and Sterilization
Both electronic and mechanical pipettes are simple to clean. The basic principle is the same, remove the tip ejection collar and the cylinder. After that you have the piston and the seal visible. Clean all the parts, relubricate, and you are ready for re-assembly. Check the performance always after opening the lower end, something might have gone wrong and the only way to be sure is to check it.
When it comes to sterilizing, mechanical pipettes can be the better option. Most mechanical pipettes can be autoclaved as they are, without disassembly. Electronic pipettes’ electronics won’t tolerate autoclaving. The lower parts of an electronic pipettes are usually autoclavable, but then you need to separate them from the handle part and reassemble afterwards. Mechanical pipettes can be transported from the autoclave inside the bag to the place of use, without risking contamination.
Always refer to manufacturers' recommendations when it comes to cleaning or sterilizing.