Abstract: An air cushion pipette comprises at least one seat configured to releasably hold a pipette tip and a displacement apparatus comprising a displacement chamber including a displacement element configured to be displaced therein. A drive apparatus is coupled to the displacement element and configured to displace the displacement element in the displacement chamber. An overstroke apparatus comprises a lower stop and is configured such that a stop element displaces the lower stop downwards when the stop element presses against the lower stop, wherein the downward displacement of the lower stop is limited to a first overstroke. A displaceable overstroke limiting element is configured to enable the displacement of the lower stop downwards by the first overstroke in a release position and limit said displacement to a second overstroke that is shorter than the first overstroke in a blocking position.

Abstract: The invention relates to a pipette with a body for receiving a displacement device, the displacement device comprising a displacement chamber and a movable boundary element for bounding a pipetting stroke of the pipette. The pipette furthermore has an operating element for setting the pipetting volume of the pipette by movement of the boundary element in the body and for performing a pipetting operation, the operating element being in operative connection with a piston movable in the displacement chamber of the displacement device. The pipette furthermore comprises a counter for displaying the set pipetting volume and a locking mechanism for locking and/or unlocking volume setting by the operating element. It is provided that, on actuation of the operating element, the operating element is configured to perform a pipetting operation, to transfer the locking mechanism into a locked position and to lock adjustment of the pipetting volume.