Devices, systems and methods for time domain multiplexing of reagents

Abstract

Time dependent iterative reactions are carried out in microscale fluidic channels by configuring the channels such that reagents from different sources are delivered to a central reaction zone at different times during the analysis, allowing for the performance of a variety of time dependent, and/or iterative reactions in simplified microfluidic channels. Exemplary analyses include the determination of dose responses for biological and biochemical systems.

What is claimed is:  
     
         1 . A device for performing a plurality of successive reactions on at least a first reagent, comprising: 
 a body structure;    a first reaction zone disposed within the body structure, the first reaction zone being fluidly connected to a source of the at least first reagent;    a source of a second reagent in fluid connection to the first reaction zone;    a source of a third reagent in fluid connection to the first reaction zone;    wherein the fluid connections between the second and third reagent sources and the reaction zone are configured to deliver a third reagent from the third reagent source to the first reaction zone subsequent to delivery of a second reagent from the second reagent source to the reaction zone.    
     
     
         2 . The device of  claim 1 , wherein the fluid connections between the second and third reagent sources and the reaction zone are configured to deliver a third reagent from the third reagent source to the first reaction zone subsequent to delivery of a second reagent from the second reagent source to the reaction zone, when subjected to a same applied driving force.  
     
     
         3 . The device of  claim 1 , wherein the fluid connection between the second reagent source and the reaction zone, and the third reagent source and reaction zone comprise first and second connector channels, respectively, wherein the second channel is longer than the first connector channel.  
     
     
         4 . The device of  claim 1 , wherein the fluid connection between the second reagent source and the reaction zone, and the third reagent source and reaction zone comprise first and second connector channels, respectively, wherein the second channel comprises a larger cross-sectional area than the first connector channel.  
     
     
         5 . The device of  claim 1 , wherein the fluid connection between the second reagent source and the reaction zone, a nd the third reagent source and reaction zone comprise first and second connector channels, respectively, wherein the second channel comprises a greater fluidic resistance than the first connector channel.  
     
     
         6 . The device of  claim 1 , wherein the fluid connection between the second reagent source and the reaction zone, and the third reagent source and reaction zone comprise first and second connector channels, respectively, wherein the second channel comprises one or more of a smaller cross-sectional area and greater length than first channel to deliver a third reagent from the third reagent source to the first reaction source subsequent to delivery of the second reagent from the second reagent source to the reaction zone.  
     
     
         7 . The device of  claim 1 , wherein the first and second reagents comprise first and second dilutions of a same reagent.  
     
     
         8 . The device of  claim 7 , wherein the first reagent comprises a lower concentration of the same reagent than the second reagent.  
     
     
         9 . The device of  claim 1 , further comprising a source of at least a fourth reagent in fluid connection with the reaction zone.  
     
     
         10 . The device of  claim 9 , wherein the fluid connection between the fourth reagent source and the reaction zone is configured to deliver a fourth reagent from the fourth reagent source to the reaction zone, subsequent to the third reagent  
     
     
         11 . The device of  claim 10 , wherein the fluid connection between the fourth reagent source and the reaction zone comprises a third connector channel, wherein the third connector channel is longer than the second connector channel.  
     
     
         12 . The device of  claim 10 , wherein the fluid connection between the fourth reagent source and the reaction zone comprises a third connector channel, wherein the third connector channel comprises a greater cross-sectional area than the second connector channel.  
     
     
         13 . The device of  claim 10 , wherein the fluid connection between the fourth reagent source and the reaction zone comprises a third connector channel, wherein the third connector channel comprises a greater fluidic resistance than the second connector channel.  
     
     
         14 . The device of  claim 1 , wherein: 
 the reaction zone comprises a first channel region, the first channel region having first and second ends, the first end being fluidly connected to the source of first reagent, and the second end being fluidly connected to a port disposed in the body structure; and    the fluid connection between the third reagent source and the reaction channel is disposed between the fluid connection between the second reagent source and the reaction channel and the port.    
     
     
         15 . The device of  claim 14 , wherein the port is configured to receive a vacuum source, for applying a vacuum to the port and first reaction channel, whereby the first, second and third reagents are drawn into and through the reaction channel.  
     
     
         16 . The device of  claim 1 , wherein the first reagent comprises at least a first component of a biochemical system.  
     
     
         17 . The device of  claim 16 , wherein the at least first component of a biochemical system comprises cells.  
     
     
         18 . The device of  claim 16 , wherein the at least first component of a biochemical system comprises complementary members of a specific binding pair.  
     
     
         19 . The device of  claim 18 , wherein the specific binding pair is selected from a ligands and its receptor, an antibody and its antigen, and complementary single stranded nucleic acid sequences.  
     
     
         20 . The device of  claim 16 , wherein the at least first component of a biochemical system comprises an enzyme and its substrate.  
     
     
         21 . The device of  claim 1 , wherein at least one of the reaction zone and fluid connections between the second and third reagent sources and the reaction zone comprise at least one microscale cross-sectional dimension.  
     
     
         22 . A kit, comprising: 
 the device of  claim 1;     a volume of at least the first reagent;    and packaging for containing the microfluidic device and the volume of first reagent.    
     
     
         23 . A system, comprising: 
 the device of  claim 1;  and    a material transport system for transporting the first reagent through the reaction zone and for transporting the second reagent and third reagent from the second and third reagent sources, respectively, into the reaction zone.    
     
     
         24 . The system of  claim 23 , wherein the material transport system comprises a vacuum source fluidly connected to the reaction zone.  
     
     
         25 . The system of  claim 23 , wherein the material transport system comprises an electrical controller operably coupled to the device of  claim 1 , for applying a voltage gradient between the second and third reagent sources and the reaction zone.  
     
     
         26 . A device, comprising: 
 a reaction zone;    a source of first reagent;    a source of second reagent;    a first fluid path connecting the first reagent source to the reaction zone, the first fluid path configured to deliver first reagent to the reaction zone under a driving force at a first time point; and    a second fluid path connecting the second reagent source to the reaction zone, the second fluid path configured to deliver the second reagent to the reaction zone under the driving force at a second time point, the second time point being subsequent to the first time point.    
     
     
         27 . The device of  claim 26 , wherein at least a portion of the first fluid path comprises at least a portion of the second fluid path.  
     
     
         28 . The device of  claim 26 , further comprising a port disposed in the microfluidic device, the port being fluidly connected to the reaction zone.  
     
     
         29 . The device of  claim 28 , wherein the port is configured to receive a pressure source for applying a pressure differential between the first and second reagent sources and the reaction zone, the pressure differential comprising the driving force.  
     
     
         30 . The device of  claim 29 , wherein the pressure source comprises a vacuum source.  
     
     
         31 . The device of  claim 28 , wherein each of the source of first reagent, source of second reagent, and the port is configured to receive an electrode disposed therein, the electrode being in contact with a fluid disposed in the port, the electrodes providing a potential gradient between the first and second reagent sources and the port.  
     
     
         32 . The device of  claim 26 , wherein the reaction zone comprises a first reaction channel having first and second ends, the device further comprising a source of a third reagent fluidly connected to the first end of the reaction channel, and a port fluidly connected to the second end of the first reaction channel.  
     
     
         33 . The device of  claim 32 , wherein the first and second reagent sources are in fluid connection with the reaction channel at a single point along the reaction channel.  
     
     
         34 . The device of  claim 32 , wherein the first and second reagent sources are in fluid communication with the reaction channel at first and second points along the reaction channel, respectively.  
     
     
         35 . The device of  claim 28 , wherein at least one of the reaction zone, the first fluid path and the second fluid path comprise a channel having at least one microscale cross-sectional dimension.  
     
     
         36 . A method of performing, successive reactions in a microfluidic device, comprising: 
 providing a device which comprises a reaction zone disposed within the microfluidic device, wherein the reaction zone is in fluid communication with a source of first reagent, a source of second reagent and a source of third reagent, the fluid connection between the second and third reagent sources and the reaction one being configured to deliver the second reagent to the reaction zone prior to the third reagent;    applying a driving force to at least one of the reaction zone, the first reagent source, the second reagent source and the third reagent source to flow the first reagent through the reaction zone, introduce the second reagent into the reaction zone causing a first reaction between the first reagent and the second reagent, and subsequently introduce the third reagent into the reaction zone to cause a reaction between the first reagent and the third reagent.    
     
     
         37 . A method of performing, successive reactions in a microfluidic device, comprising: 
 providing a device which comprises a reaction zone disposed within the microfluidic device, wherein the reaction zone is in fluid communication with a source of first reagent, a source of second reagent and a source of third reagent, the fluid connection between the second and third reagent sources and the reaction one being configured to deliver the second reagent to the reaction zone prior to the third reagent;    applying a driving force to at least one of the reaction zone, the first reagent source, the second reagent source and the third reagent source to flow the first reagent through the reaction zone, introduce the second reagent into the reaction zone causing a first reaction between the first reagent and the second reagent to produce a first product, and subsequently introduce the third reagent into the reaction zone to cause a reaction between the first product and the third reagent.    
     
     
         38 . A method of determining a dose response of a first reagent on a biochemical system, comprising: 
 providing a device that comprises a body structure, a first reaction zone disposed within the body structure, the first reaction zone being fluidly connected to a first reagent source, a second reagent source and a third reagent source, the first reagent source comprising a first reagent, the second reagent source comprising a second reagent at a first concentration and the third reagent source comprising the second reagent at a second concentration greater than the first concentration, wherein the fluid connection between the second reagent source and the reaction zone and the third reagent source and the reaction zone are configured to deliver the second concentration to the reaction zone subsequent to delivering the first concentration of the second reagent to the reaction zone;    detecting an effect of each of the first concentration of the second reagent and the second concentration of the second reagent on the first reagent within the reaction zone; and    generating a dose response curve from the detected effect.    
     
     
         39 . A microfluidic system comprising: 
 a microfluidic device that comprises a body structure having at least a first reaction channel disposed therein, the reaction channel being in fluid communication with a source of at least a first component of a biochemical system; and    a detection system for detecting a reaction at a plurality of different points along the reaction channel.    
     
     
         40 . The microfluidic system of  claim 39 , wherein the reaction channel comprises a serpentine channel portion, and the detection system scans across adjacent portions of the serpentine channel portion.  
     
     
         41 . The microfluidic system of  claim 39 , wherein the first reaction channel is also in fluid communication with a plurality of sources of test compounds.