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

Abstract

The present disclosure provides a cartridge and method to move fluids within the cartridge that simplifies the design and removes the need for any internal valves or metering devices. The design is amenable to injection molded manufacturing lowering cost for large volume manufacturing. The design can be adapted to carry out both sample preparation and detection of biological substances including nucleic acids and proteins.

1 - 35 . (canceled) 
     
     
         36 . A method for a performing biological assay, comprising:
 providing a disposable sample handling cartridge having at least one set of processing chambers with each set of processing chambers including an upper processing chamber located on top of a lower processing chamber separated by a porous substrate, 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, the porous substrate being constructed of material containing pores selected to provide a uniform resistance to flow across its entire surface such that at a defined pressure differential across the porous substrate, liquids will pass through the pores but gases will not, the porous substrate having analyte specific receptors bound in said pores, a pneumatic port mounted on a top of the upper processing chamber, a pneumatic port mounted on a top of the lower processing chamber;   applying a differential pressure between one or more reagent chambers, a sample chamber and the upper processing chamber for moving liquids containing reagents from one or more reagent chambers and liquid containing sample from the sample chamber through capillary channels to the upper processing chamber, the differential pressure being applied via pneumatic ports on top of said one or more reagent chambers and on top of said sample chamber and said pneumatic port on said upper processing chamber,   applying a differential pressure between the upper processing chamber and the lower processing chamber, via said pneumatic ports for moving the liquids through the porous substrate from the upper processing chamber to the lower processing chamber with the differential pressure being selected to force the liquid through the porous substrate but not gas;   applying a differential pressure between the lower processing chamber and a waste chamber for moving liquids from the lower processing chamber to the waste chamber via a pneumatic port on top of said waste chamber and said pneumatic port on top of said lower processing chamber; and   detecting for analytes bound to the analyte specific receptors on the porous substrate.   
     
     
         37 . The method according to  claim 36  wherein the biological assay is a nucleic acid assay. 
     
     
         38 . The method according to  claim 36  wherein the biological assay is a protein assay. 
     
     
         39 .- 63 . (canceled) 
     
     
         64 . The method according to  claim 36  wherein said porous substrate has a plurality of pores with a cross section and size of individual pores configured to provide flow resistance at liquid-gas interfaces to provide control of flow of liquid through the porous substrate and block flow of gas bubbles through the porous substrate. 
     
     
         65 . The method according to  claim 64  wherein the porosity of said porous substrate and the thickness of said porous substrate is selected to provide a required flow rate for a selected range of differential pressure. 
     
     
         66 . The method according to  claim 36  wherein the porous substrate is a generally planar porous substrate material having opposed surfaces and pores extending through a thickness of said porous substrate in which the pores have a greater width near a surface of the substrate facing into the lower processing chamber compared to a width of the pores on the opposed surface facing into the upper processing chamber, thereby improving a collection efficiency of light emitted from light emitting constituents from within the pores. 
     
     
         67 . The method according to  claim 36  wherein said lower processing chamber includes an optical window along a bottom wall of said lower processing chamber for permitting light to enter and exit said lower processing chamber, said optical window is spaced from a bottom planar surface of said porous substrate defining a constant gap therebetween, said bottom planar surface being viewable by a detection device spaced from said optical window for detecting optical emissions from said porous substrate. 
     
     
         68 . The method according to  claim 36  wherein said porous substrate is functionalized with binding substances bound in pores of the porous substrate selected to interact with preselected analyte species in the liquid. 
     
     
         69 . The method according to  claim 36  wherein said porous substrate includes organized patterns of different analyte-specific binding agents bound in different regions of the bottom planar surface of the porous substrate. 
     
     
         70 . The method according to  claim 69  wherein said different binding agents are contained within the interior surfaces of the widened pores and they, or materials specifically bound to them, emit light, the optical characteristics of which may be different for said different binding agents. 
     
     
         71 . The method according to  claim 36  wherein said porous substrate is a rigid porous substrate. 
     
     
         72 . The method according to  claim 71  wherein said rigid porous substrate is a porous silicon dioxide substrate. 
     
     
         73 . The method according to  claim 36  wherein said one or more reagent chambers are 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, and wherein a volume of the upper processing chamber is 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; 
     
     
         74 . The method according to  claim 73  wherein transport of liquids between said one or more reagent chambers, upper and lower processing chambers and said waste 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 waste chamber.