Disposable bioassay cartridge and method of performing multiple assay steps and fluid transfer within the cartridge

A disposable sample handling cartridge for performing multiplex biological assays, comprising:

• a) a processing chamber including
• an upper processing chamber having a preselected volume and having a pneumatic port mounted on a top of the upper processing chamber;
• a lower processing chamber, said upper processing chamber being located on top of said lower processing chamber, and including a pneumatic port mounted on a top of the lower processing chamber;
• b) a porous substrate positioned to separate the upper processing chamber from the bottom processing chamber with the porous substrate forming the bottom of the upper processing chamber wherein the porous substrate is connected to a body of the upper processing chamber in such a way that fluids can only exit through the bottom of the upper processing chamber into lower processing chamber by passing through the porous substrate when an applied pressure differential across the porous substrate exceeds a critical pressure, said porous substrate projecting down into said lower processing chamber to form at least one head space in the lower processing chamber adjacent to the side of the portion of the porous substrate projecting into the lower processing chamber;
• c) one or more reagent chambers being in flow communication with said upper processing chamber by capillary channels configured to terminate in a top of the upper processing chamber such that they are located above a level of liquid in the upper processing chamber while performing assays, each of said one or more reagent chambers including at least one pneumatic port located on a top of each of said one or more reagent chambers, a volume of the upper processing chamber being selected to be greater than a liquid volume provided by the one or more reagent chambers to provide a head space in an upper portion of the upper processing chamber into which the capillary channels terminate;
• d) an additional chamber in flow communication with said lower processing chamber by a capillary channel terminating in a top of the additional chamber, said additional chamber including a pneumatic port mounted on a top of the additional chamber;
• and
• e) wherein transport of liquids between said one or more reagent chambers, processing chambers and said additional chamber are controlled by application of pneumatic pressures with magnitudes required to overcome capillary pressure resistance between said one or more reagent chambers, processing chambers and said additional chamber.