Coaxial needle and pipetting device

摘要

A two-part coaxial needle for a pipetting device, in particular for use in microscopy of cell probes, makes it possible both to inject a liquid into a pipetting container and to remove by suction a liquid from the pipetting container. Both the drive for lowering the coaxial needle into the pipetting container, and injection and removal by suction of the liquid take place pneumatically by way of only one pressure source. The design of the coaxial needle and of the drive systems makes possible fast and reliable pipetting with high metering accuracy and a particularly compact pipetting unit which without mutual interference can be used with a multitude of widely-used microscope types.

主权项

1. A pipetting device comprising a pipetting unit, the pipetting unit comprising:
a hollow suction conduit for drawing off a liquid from a pipetting container, and a hollow insertion lance that encloses the suction conduit at least in part so that, between an exterior wall of the suction conduit and an interior wall of the insertion lance, a liquids duct for feeding a liquid into a pipetting container is formed, wherein the insertion lance comprises a first open end for the delivery of a liquid to a pipetting container, and a second open end for the uptake of the liquid, wherein the hollow suction conduit and the hollow insertion lance are configured to provide a coaxial needle, the pipetting unit further comprising:
a first drive unit connected to the insertion lance; anda second drive unit connected to the suction conduit; wherein the pipetting unit is configured to be moved in a direction perpendicular to an axial direction of the coaxial needle.