Pipettes

A pipette (sometimes spelled pipet) is a laboratory tool commonly used in chemistry, biology and medicine to transport a measured volume of liquid, often as a media dispenser. Pipettes come in several designs for various purposes with differing levels of accuracy and precision, from single piece glass pipettes to more complex adjustable or electronic pipettes. Many pipette types work by creating a partial vacuum above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense liquid. Measurement accuracy varies greatly depending on the style.

The first simple pipettes were made in glass, such as Pasteur pipettes. Large pipettes continue to be made in glass; others are made in squeezable plastic for situations where an exact volume is not required.

The first micropipette was patented in 1957 by Dr Heinrich Schnitger (Marburg, Germany). The founder of the company Eppendorf, Dr. Heinrich Netheler, inherited the rights and started the commercial production of micropipettes in 1961. The adjustable micropipette is a Wisconsin invention developed through interactions among several people, primarily inventor Warren Gilson and Henry Lardy, a professor of biochemistry at the University of Wisconsin-Madison.

Although specific descriptive names exist for each type of pipette, in practice any type of pipette will merely be referred to as a "pipette" and the desired device will be obvious from context. Sometimes, pipettes that dispense between 1 and 1000 μl are distinguished as micropipettes, while macropipettes dispense greater volumes.

Air displacement micropipettes are a type of adjustable micropipette that deliver a measured volume of liquid; depending on size, it could be between about 0.1 µl to 1000 µl (1 ml). These pipettes require disposable tips that come in contact with the fluid. The four standard sizes of micropipettes correspond to four different disposable tip colors:

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Wikipedia