Graduated Pipettes are pipettes equipped with a volume scale and suitable to be used for different liquid volumes. Through their capacity of different liquid volumes, they are more flexible, but also more inaccurate than bulb pipettes which only have one or two marks for a determined volume.
German physician Heinrich Schnitger developed the microliter or piston stroke pipette (PSP) in 1957.A microliter pipette works more precisely than conventional glass pipettes and is suitable for the dosage of even the smallest volumes from 0.1μl to 5000μl. Microliter pipettes work according to the principle of displacement: The device contains a moving piston that, when pushed down, displaces the air column below it or pulls it upwards in the upward movement and thereby also the liquid to be pipetted into the inserted pipette tip. This pipette tip is a disposable plastic article and is the only component to get in contact with the liquid. Directly displaced piston stroke pipettes are suitable for pipetting even very viscous solutions and use special pipette tips with a built-in piston, which directly comes into contact with the medium and thus eliminates the air cushion. Among other things, we supply microliter pipettes from the well-known manufacturers Eppendorf, Brand, Vitlab and many others.