Pipette device

Abstract

A pipette device having an elongate casing with a handle portion at its upper end and an actuating button slidably mounted in the casing and projecting outwardly from the casing at the upper surface of the handle portion. The actuating button is coupled to a piston that is slidably movable within a cylinder disposed within the casing. The lower end of the casing mounts a conical adapter member for receiving replaceable pipette tip members. The actuating button is urged upwardly so that it projects from the upper end of the casing by spring means. A detent means within the casing allows to depress the actuating button into the casing against the spring means by a first distance corresponding to the displacement of the pipetting volume. The detent means may be released by exerting a momentarily increased downward pressure onto the actuating button so that upon release of the detent means the actuating button may be despressed further into the casing by a second distance against the spring means to blow out residual fluid and/or to eject a pipette tip member mounted on the adapter. The actuating button may also be adapted to be rotated with respect to the casing to define various different pipetting volumes by the engagement of corresponding stops with an abutment within the casing. The detent means may consist of magnetic or mechanical engagement members.