Tube bottom sensing for small fluid samples

摘要

A pipetting station having a bottom sensing device is provided in conjunction with one of any known liquid level sensing devices. The bottom sensing device includes a pipetting probe spring mounted to a pipetting arm of the pipetting station. The bottom sensing device also includes a sensor for determining when a pipetting tip of the pipetting probe is in contact with a bottom of a tube. The bottom sensing device permits the pipetting probe to measure an exact volume of fluid in the tube by allowing the pipetting tip to be lowered to the bottom of the tube beyond the sensed fluid level.