Using a Volumetric Pipet

Using a Volumetric Pipet

Pipets come in a variety of sizes which usually range from 1 ml up to 100 ml.

1. Rinse the pipet two or three times with the liquid you wish to transfer. Do this by drawing a small amount of liquid into the pipet, turning the pipet horizontally and rotating it so that the liquid contacts the entire inside surface of the pipet. Let the liquid drain into a waste container.

2. If you are right handed place the pipet in your right hand and the pipet bulb in your left (left handed people do the opposite).

3. Squeeze the bulb and place it over the end of the pipet. The pipet should not be forced into the hole in the pipet bulb. A satisfactory seal can be made if the two are pushed up against each other.

4. Place the end of the pipet well below the surface of the liquid to be transferred and gently release the bulb. Liquid should be drawn up into the pipet. Allow the liquid to rise above the inscribed line on the pipet.

5. Quickly remove the bulb from the pipet (this is why you don't push the pipet into the bulb) and cover the opening with your right index finger.

6. Remove the pipet from the liquid and wipe any droplets off the side of the pipet.

7. Gently release the seal with your finger and allow the liquid to drain until the liquid level reaches the inscribed mark. This is most easily accomplished by releasing the pressure of your finger and rotating the pipet between your fingers.

8. Touch the pipet to the surface of the liquid or side of the container to remove any partial drops still clinging to the pipet.

9. Place the tip of the pipet into the receiving vessel and remove your finger to allow the liquid to drain. Touch the pipet once to the side of the vessel. There will be a small amount of liquid in the tip. Most pipets are calibrated to account for this liquid.

10. Rinse the pipet with water to clean it.