Microfluidic assay devices and methods

Abstract

A microfluidic device adapted to perform many simultaneous binding assays including but not limited to immunological experiments, such as ELISA assays, with minimal cross-talk between primary and secondary antibodies.

1 . A microfluidic chip comprising: 
 a plurality of flow channels formed as a matrix defining reaction chambers that are arranged in a plurality of fluidic columns and a plurality of fluidic rows,    a first plurality of valves that upon actuation turn off fluidic communication through the fluidic rows of the matrix while permitting flow through the fluidic columns of the matrix,    a second plurality of valves that upon actuation turn off fluidic communication through columns of the matrix while permitting flow through the fluidic rows of the matrix, and    a plurality of dedicated flushing channels that are addressable to switch between flushing the fluidic columns and flushing the fluidic rows.    
     
     
         2 . A microfluidic chip according to  claim 1  wherein the chip is partially comprised of an elastomeric material.  
     
     
         3 . A microfluidic chip according to  claim 2  wherein the chip is fully comprised of an elastomeric material.  
     
     
         4 . A microfluidic chip according to  claim 2  wherein the elastomeric material is non-opaque.  
     
     
         5 . A microfluidic chip according to  claim 2  wherein each of the fluidic columns comprises a first row flow channel segment that defines the top of each of the fluidic columns and each of the fluidic columns has a last row flow channel segment that defines the bottom of each of the fluidic columns wherein the first row flow channel segments each comprise a first flow channel segment connection channel in fluid communication with the first row flow channel segment for each column of the matrix and wherein each of the fluidic columns the last row flow channel segments comprise a second flow channel segment connection channel in fluid communication with the last row flow channel segments for each fluidic column of the matrix.  
     
     
         6 . A microfluidic chip according to  claim 5  wherein each of the plurality of first row flow channel connection segments is fluidically bifurcated into a first inlet channel and a first outlet channel and each of the plurality of last row flow channel connection segments is fluidically bifurcated into a second inlet channel and a second outlet channel.  
     
     
         7 . A microfluidic chip according to  claim 6  wherein each first inlet channel, each first outlet channel, each second inlet channel, and each second outlet channel further comprises an addressable valve for stopping fluidic communication through each first inlet channel, each first outlet channel, each second inlet channel, and each second outlet channel.  
     
     
         8 . A microfluidic chip according to  claim 7  wherein each reaction chamber defined in the matrix comprises a first flush inlet and a second flush inlet.  
     
     
         9 . A microfluidic chip according to  claim 8  wherein each reaction chamber is comprised of a flow channel with a first end opening and a second end opening that define a length of the reaction chamber wherein ½ of the length of the reaction chamber defines a reaction chamber midpoint demarking a first zone of the reaction chamber and a second zone of the reaction chamber wherein the first flush inlet fluidically communicates with the first zone of the reaction chamber and the second flush inlet fluidically communicates with the second zone of the reaction chamber.  
     
     
         10 . A microfluidic chip of  claim 9  wherein the communication of the first flush inlet with the reaction chamber and the communication of the second flush inlet with the reaction chamber is spaced a distance that is about ¼ or greater of the length of the reaction chamber.  
     
     
         11 . A microfluidic chip according to  claim 9  wherein the communication of the first flush inlet with the reaction chamber and the communication of the second flush inlet with the reaction chamber is spaced a distance that is about ½ or greater of the length of the reaction chamber.  
     
     
         12 . A microfluidic chip according to  claim 1  wherein the volume of each reaction chambers is between about 0.01 nL to about 10 nL.  
     
     
         13 . A microfluidic chip according to  claim 12  wherein the volume of each reaction chambers is between about 0.20 nL to about 5 nL.  
     
     
         14 . A microfluidic chip according to  claim 13  wherein the volume of each reaction chambers is between about 0.25 nL to about 2 nL.  
     
     
         15 . A microfluidic chip according to  claim 12  wherein the chip comprises 432 or greater reaction chambers.  
     
     
         16 . A microfluidic chip according to  claim 12  wherein the chip comprises 864 or greater reaction chambers.  
     
     
         17 . A microfluidic chip according to  claim 12  wherein the chip comprises 4608 or greater reaction chambers.  
     
     
         18 . An immunomatrix chip comprising the microfluidic chip according to  claim 1  wherein a plurality of reaction chambers contain an immunological assay reagent.  
     
     
         19 . A microfluidic chip for performing immunoassays comprising: 
 a plurality of reaction chambers configured to reduce antibody crosstalk, the chambers having a volume of less than 5 nL per chamber and wherein the immunoassay sensitivity is less than about 1×10 3  pg/mL and the dynamic range of the assay is equal to or greater than about 1×10 2 .    
     
     
         20 . The chip according to  claim 19  wherein the chambers have a volume of less than 1 nL.  
     
     
         21 . The chip according to  claim 19  wherein the reaction chambers have a plurality of flow channel inlets comprising a first inlet for the introduction of a primary antibody and a second inlet for the introduction of a secondary antibody.  
     
     
         22 . The chip according to  claim 21  wherein the reaction chamber comprises a third inlet for the introduction of a sample.  
     
     
         23 . The chip according to  claim 19  wherein the microfluidic chip is comprised of an elastomer.  
     
     
         24 . The chip according to  claim 21  wherein the microfluidic chip is comprised of an elastomer.  
     
     
         25 . The chip according to  claim 24  further comprising a control channel separated from a flow channel by a deflectable membrane.  
     
     
         26 . The chip according to  claim 25  wherein each flow channel that is in communication with the reaction chamber is separated from a control channel by a deflectable membrane.  
     
     
         27 . The chip according to  claim 26  further comprising a binding protein.  
     
     
         28 . The chip according to  claim 27  further comprising a primary antibody bound to the binding protein.  
     
     
         29 . The chip according to  claim 26  further comprising a linker molecule and a reagent wherein the linker covalently attaches the reagent to the reaction chamber.  
     
     
         30 . A microfluidic device comprising a microfluidic chip according to  claim 1  in fluidic communication with a plurality of flow channels on a rigid carrier.  
     
     
         31 . A microfluidic device according to  claim 30  wherein a plurality of flow channels on the rigid carrier are in fluid communication with liquid reservoir wells on the rigid carrier.  
     
     
         32 . A microfluidic device comprising a microfluidic chip according to  claim 16  in fluidic communication with a plurality of flow channels on a rigid carrier.  
     
     
         33 . A microfluidic device comprising a microfluidic chip according to  claim 17  in fluidic communication with a plurality of flow channels on a rigid carrier.  
     
     
         34 . A microfluidic device comprising a microfluidic chip according to  claim 19  in fluidic communication with a plurality of flow channels on a rigid carrier.  
     
     
         35 . A microfluidic device according to  claim 31  further comprising an accumulator for the storage of fluidic pressure attached to the rigid carrier, the accumulator being in fluidic communication with the microfluidic chip.  
     
     
         36 . A microfluidic device according to  claim 32  further comprising an accumulator for the storage of fluidic pressure attached to the rigid carrier, the accumulator being in fluidic communication with the microfluidic chip.  
     
     
         37 . An assay system comprising a microfluidic device according to  claim 30  and a programmable reader.  
     
     
         38 . An assay system comprising a microfluidic device according to  claim 32  and a programmable reader.  
     
     
         39 . An assay system according to  claim 38  further comprising a pressure source external to the microfluidic device.  
     
     
         40 . An assay system according to  claim 39  wherein the programmable reader is configured for real time data point collection.  
     
     
         41 . A microfluidic device for performing 432 or greater simultaneous immunoassays in less than 6 hours.  
     
     
         42 . A microfluidic device for performing 864 or greater simultaneous immunoassays in less than 6 hours.  
     
     
         43 . A microfluidic device for performing 864 or greater simultaneous immunoassys in less than 6 hours with a limit of detection of 10 μg/mL or lower for sample antigen or antibody.