Uso De La Micropipeta

Introduction to Techniques Use of Pipetmen
In biochemistry, the ability to accurately and reproducibly measure and transfer small volumes of liquids is critical for obtaining useful results. Forvolumes less than 1 ml, the most common method for measuring liquid volumes involves the use of a device known as a pipetman. (Note: “Pipetman” is the brand name of the most commonly used of these typesof pipets; however, all of these pipetting devices work on similar principles.) A drawing of a pipetman is shown . The devices you use may not look exactly like the one shown. The pipetmen used inthis course come in three different types: P1000, P200, and P20.

P1000 are useful for volumes from 200 to 1000 μl. P200 are useful for volumes from 20 to 200 μl. P20 are useful for volumes from 0.5 to20 μl. Make sure that you are using the correct pipetman for the volume you need. Also, make sure that the pipetman is actually set for the volume you need by looking in the “volume window”, and, ifnecessary, turning the “volume control knob” until the pipetman displays the correct volume (the pipetmen do not read your mind; because several people will use the pipets, they may not always be setas you expect them to be). Do not attempt to set pipetmen for volumes larger tan their maximum, or for volumes less than zero; doing so will damage the pipetman. All

pipetmen use disposable tips(do not pipet liquids without using the appropriate tip, because this will contaminate the pipetman and may damage it). When attaching the tip, make certain that the tip is the correct type for thepipetman you are using, and that the tip is properly seated on the end of the pipetman. Try depressing the plunger. As the plunger depresses, you will feel a sudden increase in resistance. This is thefirst “stop”. If you continue pushing, you will find a point where the plunger no longer moves downward (the second “stop”). When using the pipet, depress the plunger to the first “stop”, place the...