Pasteur pipette
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Pasteur pipettes, also known as droppers, are used to transfer small quantities of liquids. They are usually glass tubes tapered to a narrow point, and fitted with a rubber bulb at the top. Pasteur pipettes come in various lengths. They are sold in boxes of hundreds, and are generally considered cheap enough to be disposable. However, so long as the glass point is not chipped, the Pasteur pipette may be washed and reused indefinitely.
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[edit] Plastic Pasteur pipettes
The stems and bulbs of Pasteur pipettes made of plastic come in a single piece. There are different sizes. The volumes are usually marked on the stem, though the markings are rather crude and are not particularly accurate.
Plastic Pasteur pipettes are often used in biology where most media are aqueous, and solvent resistance is not important. They are hard to wash, and are usually discarded with other biohazard waste after each use.
[edit] Microscale use
The constriction toward the tip of the Pasteur pipettes may be plugged with a bit of tissue paper or cotton wool to filter off solids from small amounts of liquids. The use of celite is optional. The bulb can be attached and squeezed to help viscous solutions filter more rapidly.
With a bit of skill, Pasteur pipettes may also be used for microscale column chromatography. With appropriately fine silica gel, the bulb may be squeezed for microscale flash column chromatography.[1]
[edit] See also
[edit] References
- ^ University of Colorado at Boulder, Procedure for Microscale Flash Column Chromatography. Accessed 1 Nov 2006.
