When a chemist needs to measure or move liquids and chemicals with an extreme degree of ease, reliability and accuracy and without risk of contamination, the lab tool of choice is clear: the humble pipette.
Perhaps more colloquially referred to as a liquid dropper, it’s a surprise to some to learn that the first pipettes were devised as recently as the 1940s. That was when famous French microbiologist Louis Pasteur figured out that the simple physics phenomenon of air displacement is something that can be controlled with high precision at the tips of a chemist’s fingers. And in the lab today, many chemists still refer to the most basic air droppers as a Pasteur pipette.
Sure, more sophisticated and modern digital micropipettes take the concept several steps forward and are also available in single and multi-channel variants and with plunger functionality rather than a simple air cushion. But for the simplest liquid handling, measuring and transferral tasks, a Pasteur pipette probably makes the most practical and affordable sense.
Essentially, a basic pipette:
* Is a glass or plastic tube – normally lab-grade polypropylene
* Is tapered to a narrow opening at the lower end
* Seamlessly shaped for the air cushion or fitted with a plastic or rubber cushion bulb.
Using a Pasteur pipette, meanwhile, is just as simple as it looks:
- Affix the bulb end if necessary, ensuring it’s fitted no deeper than the pipette’s top segment
- Squeeze the bulb end and insert into the liquid you want to transfer
- Keep the pipette upright and lightly release your grip on the bulb/top section. Don’t draw so much liquid in that it enters the top segment/bulb.
- Transfer your liquid to the destination container and gently squeeze the bulb section again, ensuring the pipette is always kept fully upright.
Perhaps the best part of simple polypropylene Pasteur pipettes is that they’re super-cheap and therefore able to be bought in bulk, they won’t break or shatter or cause you skin injuries, they’re fully compatible with autoclaves and they can easily and affordably be bought in the shape, size, style and configuration you require.
Did you know a simple pipette can be used for:
Liquid purification?: Some chemists place liquids in pipettes together with glass wool or activated carbon to trap contaminants and purify the liquids.
Liquid storage?: By sealing the pipette’s tip end with a flame, it’s an easy and affordable purpose-made container for storage and freezing.
Medicine administration?: It’s the perfect way to drop in liquid drip by drip into ears, nostrils and eyes.
At home?: From the kitchen to the classroom to the amateur fragrance/perfuse chemist, there are 1000 other potential uses for the easiest way to accurately and safely measure and transfer liquids to no risk of cross contamination.
Are you ready to grab your pipettes? It all depends on the required volume, vessel and liquid type, task complexity and product quality, so if you need a little extra help don’t be shy to get in touch with our friendly industry guides and visit RS to get your pipettes today.
