Pipettes are a common sight in any chemistry, biology or a physics laboratory. Popularly known as pipette, pipettor, chemical dropper or a pipet, it is a common laboratory tool to transfer a measured volume of liquid. They are available in different designs for different purposes.
Micropipettes are those dispensing between 1 and 1000 μl and in contrast, macropipettes dispense greater volumes. Depending upon the sizes, capacity and style, pipettes is of following types:
• Air displacement micropipettes
• Positive displacement pipette
• Volumetric pipettes
• Graduated pipettes
• Pasteur pipette
• Transfer pipettes
• Van Slyke pipette
• Ostwald–Folin pipette
• Glass micropipette
• Extremely low volume pipettes
• Microfluidic pipette
But before using a pipette, it is extremely necessary that you master their use in order to be successful in the lab experiments.
Parts of Micropipette
a) Plunger button
b) Tip ejector button
c) Volume adjustment dial
d) Digital volume indicator
f) Attachment point for a disposable tip
Sizes of micropipette
Basically, micropipettes come in three different sizes of varying capacity. They are P20, P200 and P1000. The sizes are noted on the top of the plunger button (as mentioned earlier, part a)
You should always remember that liquids are never drawn directly into the shaft of the pipette. For this, a disposable plastic tips are attached to the shaft and for adjusting the volume of the liquid, there is a black volume adjustment dial near the top of the micropipette.
There are two sizes of tips. The larger blue tips are used for the P1000 and the smaller clear tips are used for the P20 and P200. You should also take care of not contaminating the tips, for example: – close the box of the tips (racked in), after the use so that airborne contamination can be prevented.
How to insert a tip
Before inserting a tip, you should keep some essential points in mind as given below:-
• Select the correct size tips.
• Open the box without touching the tips with your hands.
• Insert the micropipette shaft into the tip and press down firmly. This will attach the tip to the shaft.
• Remove the micropipette, with the tip attached.
• Close the box without touching the tips with your hands
• Remember, it is better to handle something carefully rather than doing it like a defaulter.