Patent ID: 7185551

Claim:
A pipette module comprising: a channel block having at least one passage extending therethrough; a rod sized, shaped and aligned to pass into the channel block passage; a cylinder having a passage extending therethrough, the cylinder sized, shaped and aligned to pass into the channel block passage from the end opposite the end into which the rod passes; a chamber defined by the channel block, rod, and cylinder, having a volume which is variable during the pipetting operation of the pipette module, with a first part of the chamber variable by relative movement of the channel block relative to the fixed relative positions of the rod and cylinder, and with a second part of the chamber variable by relative movement of the cylinder relative to the fixed relative positions of the rod and channel block; a tip having a passageway therethrough, extending downwardly from the bottom of the cylinder; and an extension mandrel with a passageway extending therethrough, the mandrel attached at an end of the cylinder such that the passageway extending through the mandrel is aligned with the passage extending through the cylinder, wherein the mandrel reduces the internal volume within the tip.