Micropipettes are commonly used in molecular biology as well as medical tests. This come in several designs for various purposes with different level of accuracy and precision, from single piece glass pipettes to more complex adjustable or electronic pipettes. Many micropipettes work by creating a partial vacuum above the liquid holding chamber and selectively releasing this vacuum to draw up and dispense.
Micropipettes that dispense between 1 and 10000UL are termed micropipette, while micropipette dispense a grater volume of liquid. Two types of micropipettes are generally used;air displacement pipettes and positive-displacement pipettes. In particular piston drive air-displacement pipettes are micropipettes which which dispense an adjustable volume of liquid from a disposable tip. The pipettes body contains a plunger, which provide the suction to pull liquid into the tip when the piston is compressed and released. The maximum displacement of plunger is set by a dial on micropipette body, allowing the delivery volume to be changed. Larger capacity tubular pipettes, such as volumetric or graduated pipettes are used by temporarily attaching a pipetting aid. Micropipette typically handles volume in the 0.5ul to 10,000ul range, aliquot transfer and incremental dispensing in titrations, with positive displacement methods of operation.