High throughput screening assay systems in microscale fluidic devices

Abstract

The present invention provides novel microfluidic devices and methods that are useful for performing high-throughput screening assays. In particular, the devices and methods of the invention are useful in screening large numbers of different compounds for their effects on a variety of chemical, and preferably, biochemical systems.

What is claimed is:  
     
         1 . A microfluidic device, comprising: 
 a body having at least a first microscale channel disposed therein;    at least a first reservoir in fluid communication with the first microscale channel, the first reservoir having no electrodes disposed therein;    at least a second reservoir connected to the first reservoir by a second channel; and    at least a first electrode place into contact with a fluid disposed in the second reservoir: 
 wherein the second channel is configured to retard the movement of one or more degradable components between the electrode and the first microscale channel, the second channel comprising one or more of: 
 a cross-sectional dimension that is smaller than a cross-sectional dimension of the first channel; and  
 a cross-sectional dimension that is smaller than a cross-sectional dimension of the first channel.  
 
   
     
     
         2 . A microfluidic device, comprising: 
 a body having at least a first microscale channel disposed therein;    at least a first reservoir in fluid communication with the first microscale channel, the first reservoir having no electrodes disposed therein;    at least a second reservoir connected to the first reservoir by a second channel, wherein the second channel comprises a frit disposed therein; and    at least a first electrode place into contact with a fluid disposed in the second reservoir.    
     
     
         3 . A microfluidic device, comprising: 
 a body having at least a first microscale channel disposed therein;    at least a first reservoir in fluid communication with the first microscale channel, the first reservoir having no electrodes disposed therein;    at least a second reservoir connected to the first reservoir by a second channel; and    at least a first electrode place into contact with a fluid disrosed in the second reservoir;    wherein a fluid level in the first reservoir is higher than a fluid level in the second reservoir.    
     
     
         4 . A microfluidic device, comprising: 
 a body having at least a first channel disposed therein;    first and second reservoirs in fluid communication with first and second ends of the first channel, respectively;    first and second electrodes electrically connected to a fluid in the first and second reservoirs, respectively, to provide a voltage gradient through the first channel between the first and second reservoirs; and    wherein the first electrode is separated from the first end of the first channel by a first structure which prevents migration of an electrically degraded chemical species from a surface of the first electrode to the first end of the first channel.    
     
     
         5 . The microfluidic device of  claim 4 , wherein the first structure comprises a third reservoir disposed in the body, and a second channel fluidly connecting the third reservoir to the first reservoir, the first electrode being disposed in contact with a fluid in the third reservoir, but not disposed in the first reservoir.  
     
     
         6 . The microfluidic device of  claim 5 , wherein the third reservoir comprises a level of fluid that is lower than a level of fluid in the first reservoir.  
     
     
         7 . The microfluidic device of  claim 5 , wherein the second channel comprises a cross section that is smaller than a cross section of the first channel.  
     
     
         8 . The microfluidic device of  claim 5 , wherein the second channel comprises a cross section that is larger than a cross section of the first channel.  
     
     
         9 . The microfluidic device of  claim 4 , wherein the first structure comprises a frit disposed between the first electrode and the first end of the first channel.  
     
     
         10 . The microfluidic device of  claim 9 , wherein the frit surrounds the first electrode.  
     
     
         11 . The microfluidic device of  claim 9 , further comprising a third reservoir disposed in the body, and a second channel fluidly connecting the third reservoir to the first reservoir, the first electrode being disposed in contact with a fluid in the third reservoir, and the frit being disposed within the second channel.  
     
     
         12 . The microfluidic device of  claim 4 , wherein the first structure comprises a salt bridge disposed between the first electrode and the first end of the first channel.  
     
     
         13 . The microfluidic device of  claim 12 , wherein the salt bridge comprises a gel disposed within the second channel.  
     
     
         14 . The microfluidic device of  claim 13 , wherein the salt bridge comprises beads disposed within the second channel.