Microfluidic devices, methods and systems for detecting target molecules

Abstract

Microfluidic devices methods and systems for detecting a target in a fluidic component of a sample are shown. In such devices, methods and systems, the flow resistance of various channels where the sample is introduced is adjusted to control separation of the fluidic component from the sample and/or performance of assays for the detection of the target in the fluidic component in a controlled fashion. Such performance is controlled by binding affinity of the target with capture agents or diffusion of the target in the fluidic component.

1 . A microfluidic device for detecting at least one target in a fluidic component of a fluid sample, the microfluidic device comprising:
 an inlet for introducing the fluid sample in the microfluidic device,   a flowing channel in fluidic communication with the inlet, the flowing channel having a flowing channel resistance, and   an assaying channel in fluidic communication with the flowing channel, the assaying channel having an assaying channel resistance and carrying at least one capture agent or component thereof, the at least one capture agent or component thereof attached to the assaying channel, the at least one capture agent having a binding affinity for the target,   wherein   the flowing channel resistance and the assaying channel resistance are adapted to control flowing of the fluidic component from the flowing channel to the assaying channel, and   the assaying channel resistance is further adapted to allow binding of the target to the capture agent to form a detectable target capture agent binding complex, said binding controlled by at least one between said binding affinity and diffusion of said target in the fluidic component.   
     
     
         2 . The microfluidic device of  claim 1 , wherein the flowing channel resistance and the assaying channel resistance are adapted to maximize flowing of the fluidic component from the flowing channel to the assaying channel. 
     
     
         3 . The microfluidic device of  claim 1 , wherein the assaying channel comprises a first portion wherein the binding is controlled by said binding affinity and a second portion wherein the binding is controlled by said diffusion of said target molecule in the fluidic component. 
     
     
         4 . The microfluidic device of  claim 1 , wherein the fluid is blood and the fluidic component is plasma. 
     
     
         5 . The microfluidic device of  claim 1 , wherein the at least one capture agent or component thereof comprises
 a substrate polynucleotide attached to the assaying channel.   
     
     
         6 . The microfluidic device of  claim 5 , wherein the at least capture agent or component thereof further comprises
 a polynucleotide-encoded protein comprising a protein and an encoding polynucleotide attached to the protein, wherein the protein specifically binds the at least one target and the encoding polynucleotide is specifically bound the substrate polynucleotide.   
     
     
         7 . The microfluidic device of  claim 1 , wherein the at least one target comprises a plurality of targets and the at least one capture agent or component thereof comprises:
 a plurality of substrate polynucleotides attached to the assaying channel, each polynucleotide of the plurality of substrate polynucleotides being sequence specific and positionally distinguishable from another.   
     
     
         8 . The microfluidic device of  claim 7 , wherein the plurality of capture agents or component thereof further comprise
 a plurality of polynucleotide-encoded proteins, each polynucleotide-encoded protein comprising a protein and an encoding polynucleotide attached to the protein, wherein the protein specifically binds to a predetermined target of the plurality of targets and the encoding polynucleotide specifically binds to a sequence-specific and positionally distinguishable polynucleotide of the plurality of polynucleotides attached to the assaying channel, each protein and encoding polynucleotide being bindingly distinguishable from another.   
     
     
         9 . The microfluidic device of  claim 1 , wherein
 the at least one capture agent or component thereof comprises a plurality of capture agents or component thereof,   each of the plurality of capture agents bindingly distinguishable and positionally distinguishable from another, each of the plurality of capture agents specifically binding the target molecule in a capture agent target binding complex, and   the plurality of capture agents are arranged on the assaying channel so that capture agent target binding complexes are detectable along substantially parallel lines forming a bar coded pattern.   
     
     
         10 . A system for detecting at least one target in a fluidic component of a fluid sample, the system comprising
 the microfluidic device of  claim 5  and   a polynucleotide-encoded protein comprising a protein and an encoding polynucleotide attached to the protein, wherein the protein specifically binds a target and the encoding-polynucleotide specifically binds the substrate polynucleotide.   
     
     
         11 . A system for detecting at least one target in a fluidic component of a fluid sample, the system comprising
 the microfluidic device of  claim 7  and   a plurality of polynucleotide-encoded proteins, each polynucleotide-encoded protein comprising a protein and an encoding polynucleotide attached to the protein, wherein the protein specifically binds to a predetermined target of the plurality of targets and the encoding polynucleotide specifically binds to a sequence-specific and positionally distinguishable polynucleotide of the plurality of polynucleotides attached to the assaying channel, each protein and encoding polynucleotide being bindingly distinguishable from another.   
     
     
         12 . A method for detecting at least one target molecule in a fluidic component of a fluid sample, the method comprising:
 providing the fluid sample in a flowing microfluidic channel;   controlling selective flowing of the fluidic component from the flowing microfluidic channel to an assaying microfluidic channel, the assaying microfluidic channel carrying at least one capture agent or a component thereof, the at least one capture agent attached to the assaying channel, the at least one capture agent having a binding affinity for the target molecule;   contacting the at least one target molecule with the at least one capture agent in the assaying microfluidic channel for a time and under conditions to allow binding of the at least one target molecule to the at least one capture agent to form a detectable target capture agent binding complex, said binding controlled by said binding affinity or by diffusion of said target molecule in the fluidic component; and   detecting the detectable target capture agent binding complex.   
     
     
         13 . A microfluidic device for detecting at least one target in a fluidic component of a fluid sample, the microfluidic device comprising:
 an inlet for introducing the fluid sample in the microfluidic device,   a flowing channel in fluidic communication with the inlet, the flowing channel having a flowing channel resistance, and   an assaying channel in fluidic communication with the flowing channel, the assaying channel having an assaying channel resistance,   wherein   the flowing channel resistance and the assaying channel resistance are configured to control flowing of the fluidic component from the flowing channel to the assaying channel, and   the assaying channel resistance is further configured to allow attachment of a target on a surface of said assaying channel, the attached target being detectable through labeled molecules specifically binding said target.