NEEDLE GUIDE WITH CENTERING FOR SEPTUM PIERCING

摘要

A pipetting device (2) for removing fluid from a sample vessel (52) includes a pipetting needle (4) and an auxiliary cannula (18) for piercing a septum, designed to guide the pipetting needle axially through the auxiliary cannula. The pipetting device has a guide arm (6), on the lower end (10) of which is arranged an end plate (12) that is axially displaceable along the guide arm against a resilient resistance. A centering device (14) inserts into the end plate of the guide arm, and at least three centering fingers (26) with conical bevels (34) are constructed on the radial outside of the centering device, distributed around the circumference thereof, and forming a holding-down device for the sample vessel. The disclosed construction makes possible to reliably pierce the septum of a sample vessel and to easily pull the pipetting needle out of the septum again even with thin pipetting needles.

主权项

1. A pipetting device for removing sample fluid from a sample vessel that is sealed on a top side with a septum, comprising:
a pipetting needle and an auxiliary cannula configured to pierce the septum and to guide the pipetting needle axially through the auxiliary cannula, a guide arm on the lower end of which is arranged an end plate configured to axially displace along the guide arm against a resilient resistance, a centering device configured to insert into the end plate of the guide arm and having a radial outside surface disposed around a circumference on the centering device, and at least three centering fingers with conical bevels constructed on the radial outside of the centering device, distributed around the circumference of the centering device, forming a holding-down device for the sample vessel, and configured to engage around the top side of the sample vessel and from outside the sample vessel.