Calibratable Pipette

Calibratable pipette comprising a barrel and a piston (9) moving within the barrel, the piston being sealed to the barrel at a sealing point, a mechanism, for determining the upper limit of the piston movement, a mechanism for determining the lower limit of the piston movement, and a calibration function, allowing the piston stroke length to be varied so as to achieve a dispensed volume equaling the intended volume as exactly as possible, wherein the diameter of the piston or the barrel is at least in the portion passing by the sealing location.