Handheld Nanoliter Pipetting Device

Nanoliter pipette assembly. The assembly includes a housing containing a working fluid in a working fluid chamber therein and includes a moveable piston within the housing, the piston moveable by a linear actuation mechanism for contact with the working fluid. A tip portion is provided that includes a diaphragm deformable to engage an inner portion of the tip. It is preferred that the diaphragm have a projecting three-dimensional structure for direct contact with a liquid.