2. Operating principle

2.1 How it works

Piston pipettes are used to sample and dispense liquids. Single-channel piston pipettes feature a single body/piston assembly. Multi-channel piston pipettes have a piston/bottle assembly for each channel; an identical volume of liquid can be dispensed to several containers simultaneously (e.g. the wells of a microplate). Pipettes can be preset at the factory to dispense a fixed volume, or have a variable volume within a volume range.

A plastic or glass cone is fitted to the piston pipette (figure 1 ). By holding the piston up at the lower suction limit, the cone is immersed in the liquid whose volume is to be measured and dispensed. When the...