[Liquid handling with mechanical pipettes].

Dispensing very small amounts of liquid is essential in all science fields. A wide range of pipetting systems is now available, including air-cushion pipettes and positive-displacement pipettes. The precision and accuracy depends on not only the principle of pipetting systems but vapor pressure, density, viscosity or wetting behavior of the solution. Preventing contamination is also important issue. Basically, we should handle these pipettes according to maker's instruction manuals.