General Description A gun-shaped one is a classical type of pipette, which is often applied to remove small or trace amounts of liquid in a laboratory. Pipetting guns with different specifications are also designed with gun heads of various sizes. Even though manufacturers are likely to attribute to many shapes, the working principles and operation methods are almost the same. Besides, the pipette belongs to precise instruments, so it should be really carefully used and stored to prevent damage and broken measuring range. Main Categories In terms of the application, the pipetting gun can be divided into several types– micro-sampler, air cushion sampler, positive displacement, multichannel sampler, electronics, and distributors. The micro-sampler was first invented by Schnitger (a scientist at the German Institute of Physiology and Chemistry) in 1956. The later development included not only more precise displacing, but also wider varieties with respective applications, such as micro-distributor and multi-channel micro-sampler, which closely follow two physical principles as follows. (1) Sampling with air cushion (also known as piston stroke). (2) Piston positive displacement sampling without air cushion.