A micropipette is a laboratory device used to absorb and transfer small volumes of liquids, and allow their handling in different laboratory techniques. The place where it was manufactured and used for the first time was at The Carberg Laboratories in Denmark and its creation is attributed to the German Heinrich Schnitger.
The volumes that can be captured by these instruments vary according to the model and type of pipette: the most common, called p20, p200 and p1000, admit a maximum of 20, 200 and 1000 μl, respectively. Micropipettes are very useful for handling any kind of liquid because their tip can be discarded, since they use disposable plastic tips, which are usually sterile. A micropipette is made up of a push button or plunger, sucker, and liquid dispenser.
Types of micropipettes
Micropipettes are very useful in handling microvolumes, they allow pipetting in a much safer, more comfortable and more precise way than graduated or serological pipettes. Within the category of micropipettes you can find:
These are micropipettes for dispensing microvolumes from 0.5 ul to 1ml, although they are also available in a macrovolume version up to 5 ml.
Gun-type systems with autonomous rechargeable battery or with mains connection, for adapted pipetting with glass or serological pipettes. Also adaptable to Pasteur pipettes.
Positive displacement pipettes
These are conventional micropipettes like the automatic ones, but for the loading and handling of viscous solutions, in which case the integrated vacuum column action generated by the conventional micropipette is not enough. In this case there is a solid plunger inside the piston that comes into contact with the solution to be pipetted to increase the contact surface with the sample and facilitate its suction.
These are pipettes for loading large volumes and subsequent dosing of repeated volumes of reagents, culture media or any type of liquid solution.
These are pipettes that improve ergonomics when handling liquids and resemble a small dispensing robot at your fingertips. They allow the automation of repetitive processes. They facilitate repeated dosing, mixing or dilution of reagents and their maximum benefit is achieved in the Multichannel models.
How to use a micropipette correctly?
For the correct use of the micropipette, it must be taken into consideration that it has three fundamental steps in a general way. As are rest or rest, the first stop and the second stop. It is also convenient to have basic notions of how to pipette correctly with a micropipette:
- Never turn the volume indicator dial beyond the upper or lower limit of the micropipette.
- The tips are one of the most important parts of the micropipette, it is necessary to make sure that they are the correct size and are always sterile.
- Pipetting is most accurate when the instrument is held at an angle of less than 20 ̊ vertical.
- When releasing the liquid, it is recommended to rest the tip of the micropipette lightly against the test tube, thus the surface tension helps to dispense the content.
- A common operator mistake is to push the plunger to the second stop before filling the tip of the micropipette.
- It is important to check that the tip fits with minimal effort and that it comes out just as easily; It is always advisable to review the micropipette manual to avoid making mistakes.