The Pasteur pipette
A Pasteur pipette is a thin tube (a few mm in diameter) made of glass with a refined tip (capillary, more or less long). It is for single use.
A Pasteur pipette is used to transfer a small volume of liquid (very approximate volume, ranging from a few drops to a few mL).
For this it is necessary to place a rubber bulb on the end (widest) of the pipette - this will allow the volume of liquid to be taken up and then delivered to the desired container by holding the pipette over the container.
The procedure is as follows:
- the pipette with its rubber bulb is vented
- squeeze the rubber bulb, and keep it pressed down
- insert the pipette into the liquid to be withdrawn
- release the pressure on the rubber bulb gently and completely: the liquid should gradually rise in the pipette
- then hold the pipette over the container into which the liquid is to be transferred, and gradually squeeze the rubber bulb to dispense the liquid inside the pipette (holding it so that its tip touches the wall of the container will facilitate the transfer) .