Patent ID: 8067246

Claim:
A flow-through assay device comprising: a cassette consisting of a first member and a second member, wherein the first member defines a well having an upper surface and a lower surface wherein the upper surface of said well has an opening and the lower surface of said well is defined by a porous reaction membrane to which is bound one or more capture analytes and the second member consists of a body of absorbent material disposed below the lower surface of the first member; a removable chamber spaced above the first member of the cassette said removable chamber having side walls and a base defined by a membrane; and means for supporting the removable chamber above the first member in a first position and a second position, wherein the first position provides sufficient spacing between the chamber and the first member so as to not permit fluid transfer from the chamber to the body of absorbent material, and wherein the second position provides for contact between the membrane of the removable chamber and the first member to thereby permit fluid transfer from the removable chamber to the body of absorbent material.