Immunoassay assembly and methods of use
The present invention relates to an improved system for efficiently and accurately performing immunoassays, such as ELISAs. The invention provides an immunoassay assembly which includes a flow-through unit and an aspiration pump. The immunoassay flow-through unit includes an outer seal; at least one bed support; an inner seal; and a packed non-porous bed. The unit is releasably attached to an aspiration pump which enables the controlled flow rate of liquid passing through the packed bed of the flow-through unit. The invention also provides a method of using the immunoassay assembly to identify analytical targets of interest.
1. Apparatus for conducting an immunoassay or selective adsorption separation, the apparatus comprising:
an assay unit having a passage formed in its center to form 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 reaction reagent mounted on their surface;
an outlet from the assay unit having an outer diameter and located below the packed bed;
two frusto-conical sealing surfaces on an upper surface of the assay unit above and opening into the packed bed; and
a frusto-conical sample cup positioned between the two frusto-conical sealing surfaces, wherein the sample cup has a volume of from about 5 to about 100 μL;
wherein the two frusto-conical sealing surfaces comprise an upper sealing surface dimensioned to form a fluid-tight, friction seal with a pipette holder, and a lower sealing surface abutting the packed bed and dimensioned to form a fluid-tight, friction seal with a device selected from the group consisting of straight wall tubing have an outer diameter of from about 0.75 to about 1 mm, hypodermic needles having a gauge of from about 19 to 21, and pipette tips having a volume of from about 10 μL to about 200 μl; and
wherein the outer diameter of the outlet from the assay unit is dimensioned to form a fluid-tight, friction seal with the lower sealing surface when two assay units are nested together.
2. The apparatus of claim 1 , wherein the lower sealing surface is dimensioned to form a fluid-tight, friction seal with a pipette tip.