Patent ID: 8124028

Claim:
An apparatus comprising: an assay unit comprising: a packed bed; porous bed supports mounted in the assay unit at opposite ends of the packed bed; solid phase support beads located in the packed bed and having a selective-binding or reaction reagent mounted on their surface; an outlet from the assay unit having an outer perimeter and located below the packed bed; an inlet sealing surface adjacent to the packed bed; an upper section having an inside surface dimensioned to form a friction contact with an outside surface of a probe hub, and further comprising at least one raised rib extending from the inside surface of the upper section, wherein the rib defines at least one gap between the inside surface of the upper section and the outside surface of the probe hub to provide venting of air around the probe hub, and to prevent creating an air-tight seal between the upper section and the probe hub; a multi-function probe comprising: a hub; a needle with a lumen disposed within the hub and extending from it, wherein the needle is dimensioned and configured to aspirate and dispense liquid directly and to form a fluid-tight liquid seal with the inlet sealing surface of the assay unit.