Patent ID: 8747779

Claim:
A microfluidic cartridge for performing an assay of a fluid microsample to detect a clinical analyte or analytes therein, the microfluidic cartridge comprising: a cartridge body, a sample receptacle for receiving said fluid microsample, and at least one assay circuit arm, said assay circuit arm comprising: a) an intake fluidic channel joining said sample receptacle to a reaction chamber, wherein said reaction chamber is enclosed by a gas permeable, liquid impermeable stop-flow barrier and opposingly paired optical windows, said optical windows for transilluminating said reaction chamber at a defined wavelength or wavelengths by an optical interface of a host workstation when said cartridge body is docked therein; b) a downstream fluidic channel joining said reaction chamber to an actuation port configured to receive a suction pulse, said downstream fluidic channel further comprising said stop-flow barrier interposed between said reaction chamber and said actuation port, said reaction chamber and stop-flow barrier defining a fixed wettable volume within said assay circuit arm; c) a dry reagent matrix deposited on one or both of said opposingly paired optical windows in said reaction chamber, wherein said dry reagent matrix is configured to enable homogeneous dissolution operatively coupled to the filling of said fixed volume with said fluid microsample in response to said suction pulse; and d) a chromogen deposited in said rehydratable dry reagent matrix, said chromogen having an absorbance at a defined wavelength or wavelengths specific for a reaction with said clinical analyte.