Abstract: Apparatus for detection one or more analyte in a fluid sample. The apparatus includes one or more fluid including the fluid sample to be tested for the analyte(s) and one or more vessels for holding the fluid(s). The vessel includes a base at a first end, side walls extending generally perpendicularly from the base to a second end, an opening in the vessel defined by the side walls and the second end and a central axis extending from the center of the base to the center of vessel opening. The apparatus further includes a single matrix sheet including at least one capture site for capturing a specific analyte which is inserted in vessel and spaced from the central axis opposite the side walls and at least one apparatus for detection of a captured specific analyte.