Device and method for focusing solutes in an electric field gradient

Abstract

An electrophoretic device and method for focusing a charged solute is disclosed. The device includes a first chamber for receiving a fluid medium, the first chamber having an inlet for introducing a first liquid to the chamber and an outlet for exiting the first liquid from the chamber; a second chamber comprising an electrode array, the second chamber having an inlet for introducing a second liquid to the chamber and an outlet for exiting the second liquid from the chamber; and a porous material separating the first and second chambers. The device's electrode array includes a plurality of electrodes and generates an electric field gradient profile which can be dynamically controlled. In the method, a charged solute is introduced into a fluid medium followed by the application of a hydrodynamic force. Opposing the hydrodynamic force with an electric field gradient results in solute focusing in the fluid medium. The electric field gradient is generated by an electrode array by individually adjusting the electrode voltages.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A device for focusing a charged solute comprising: 
 a first chamber for receiving a fluid medium, the first chamber having an inlet for introducing a first liquid to the chamber and an outlet for exiting the first liquid from the chamber;    a second chamber comprising an electrode array, the second chamber having an inlet for introducing a second liquid to the chamber and an outlet for exiting the second liquid from the chamber; and    a porous material separating the first and second chambers.    
     
     
         2 . The device of  claim 1  wherein the first and second chambers are in liquid communication when the chambers are filled with liquid.  
     
     
         3 . The device of  claim 1  wherein the first chamber is in electrical communication with the electrode array when the chambers are filled with a conductive liquid.  
     
     
         4 . The device of  claim 1  wherein the electrode array comprises a plurality of electrodes arranged linearly along the chamber length.  
     
     
         5 . The device of  claim 4  wherein each electrode is individually controlled.  
     
     
         6 . The device of  claim 4  wherein the electrodes are pin-shaped.  
     
     
         7 . The device of  claim 4  wherein the electrodes are staple-shaped.  
     
     
         8 . The device of  claim 1  wherein the electrode array generates an electric field gradient profile.  
     
     
         9 . The device of  claim 8  wherein the electric field gradient profile can be dynamically controlled.  
     
     
         10 . The device of  claim 1  wherein the electrode array comprises an electrode array positioned on a surface of the second chamber opposing the porous material.  
     
     
         11 . The device of  claim 1  wherein the electrode array comprises a first electrode array and a second electrode array, the first and second arrays positioned on opposing surfaces of the second chamber adjacent the porous material.  
     
     
         12 . The device of  claim 1  wherein the fluid medium comprises a chromatography support material.  
     
     
         13 . The device of  claim 1  wherein fluid medium comprises a fluid selected from the group consisting of a simple fluid, a complex fluid, and a polymer solution.  
     
     
         14 . The device of  claim 1  wherein the charged solute comprises a biological solute selected from the group consisting of a protein, peptide, oligonucleotide, polynucleotide, and mixtures thereof.  
     
     
         15 . The device of  claim 1  wherein the charged solute comprises an uncharged material sorbed into a charged carrier.  
     
     
         16 . The device of  claim 1  wherein the second chamber further comprises an electrode pair, wherein the electrodes of the pair are positioned adjacent opposing ends of the electrode array.  
     
     
         17 . The device of  claim 1  further comprising a first conduit for introducing fluid media into the first chamber and a second conduit for exiting fluid media from the first chamber.  
     
     
         18 . A device for focusing a charged solute comprising: 
 a first block having a first trough machined therein for receiving a fluid medium, the first trough having an inlet for introducing a first liquid to the trough and an outlet for exiting the first liquid from the trough;    a second block having a second trough machined therein, wherein the second block comprises a electrode array positioned. in the trough, the second trough having an inlet for introducing a second liquid to the trough and an outlet for exiting the second liquid from the trough, wherein the first trough and the second trough are substantially coincident and form a channel when the first block is sealed to the second block; and    a porous material intermediate the first and second blocks, wherein the porous material divides the channel formed when the first block is sealed to the second block into a first chamber and a second chamber, the second chamber including the electrode array.    
     
     
         19 . The device of  claim 18  wherein the first and second chambers are in liquid communication when the chambers are filled with liquid.  
     
     
         20 . The device of  claim 18  wherein the first chamber is in electrical communication with the electrode array when the chambers are filled with a conductive liquid.  
     
     
         21 . The device of  claim 18  wherein the electrode array comprises a plurality of electrodes arranged linearly along the chamber length.  
     
     
         22 . The device of  claim 21  wherein each electrode is individually controlled.  
     
     
         23 . The device of  claim 21  wherein the electrodes are pin-shaped.  
     
     
         24 . The device of  claim 21  wherein the electrodes are staple-shaped.  
     
     
         25 . The device of  claim 18  wherein the electrode array generates an electric field gradient profile.  
     
     
         26 . The device of  claim 25  wherein the electric field gradient profile can be dynamically controlled.  
     
     
         27 . The device of  claim 18  wherein the electrode array comprises an electrode array positioned on a surface of the second chamber opposing the porous material.  
     
     
         28 . The device of  claim 18  wherein the electrode array comprises a first electrode array and a second electrode array, the first and second arrays positioned on opposing surfaces of the second chamber adjacent the porous material.  
     
     
         29 . The device of  claim 18  wherein the fluid medium comprises a chromatography support material  
     
     
         30 . The device of  claim 18  wherein fluid medium comprises a fluid selected from the group consisting of a simple fluid, a complex fluid, and a polymer solution.  
     
     
         31 . The device of  claim 18  wherein the charged solute comprises a biological solute selected from the group consisting of a protein, peptide, oligonucleotide, polynucleotide, and mixtures thereof.  
     
     
         32 . The device of  claim 18  wherein the second chamber further comprises an electrode pair, wherein the electrodes of the pair are positioned adjacent opposing ends of the electrode array.  
     
     
         33 . The device of  claim 18  further comprising a first conduit for introducing fluid media into the first chamber and a second conduit for exiting fluid media from the first chamber.  
     
     
         34 . The device of  claim 18  wherein the first block is sealed to the second block through bolts passing through the blocks.  
     
     
         35 . The device of  claim 18  further comprising a resilient sheet intermediate the second block and the porous material, wherein the sheet has an aperture coincident with the first and second troughs when the sheet is positioned intermediate the blocks  
     
     
         36 . The device of  claim 18  further comprising a sealant intermediate the second block and the resilient sheet.  
     
     
         37 . A method for focusing a charged solute in a fluid medium comprising: 
 introducing a charged solute into a fluid medium; and    applying an electric field gradient to the charged solute in the fluid medium to cause the charged solute to focus in a region of the medium, wherein the electric field gradient is generated by an electrode array.    
     
     
         38 . The method for  claim 37  wherein the electric field gradient is dynamically controlled.  
     
     
         39 . The method of  claim 37  wherein the electric field gradient is changed during the course of focusing the charged solute.  
     
     
         40 . The method of  claim 37  wherein the fluid medium comprises a chromatography support material.  
     
     
         41 . The method of  claim 37  wherein the fluid medium comprises a fluid selected from the group consisting of a simple fluid, a complex fluid, and a polymer solution.  
     
     
         42 . The method of  claim 37  wherein the charged solute comprises a biological solute selected from the group consisting of a protein, peptide, oligonucleotide, polynucleotide, and mixtures thereof.  
     
     
         43 . The method of  claim 37  wherein the charged solute comprises an uncharged material sorbed into a charged carrier.  
     
     
         44 . The method of  claim 37  wherein the charged solute is a component of a charged solute mixture.  
     
     
         45 . The method of  claim 37  wherein the electrode array comprises a plurality of electrodes arranged linearly along an axis parallel to direction of migration of the charged solute in the fluid medium.  
     
     
         46 . The method of  claim 45  wherein each electrode is individually controlled.  
     
     
         47 . A method for focusing a charged solute in a fluid medium comprising: 
 introducing a charged solute into a fluid medium, wherein the fluid medium is contained in a device comprising 
 a first chamber for receiving the fluid medium, the first chamber having an inlet for introducing a first liquid to the chamber and an outlet for exiting the first liquid from the chamber;  
 a second chamber comprising an electrode array, the second chamber having an inlet for introducing a second liquid to the chamber and an outlet for exiting the second liquid from the chamber; and  
 a porous material separating the first and second chambers; and  
 applying an electric field gradient to the charged solute in the fluid medium to cause the charged solute to focus in a region of the medium.  
   
     
     
         48 . The method of  claim 47  wherein the first liquid is an eluant buffer.  
     
     
         49 . The method of  claim 47  wherein the second liquid is a coolant buffer.  
     
     
         50 . The method of  claim 47  wherein the first liquid is the same as the second liquid.  
     
     
         51 . The method of  claim 47  wherein the first liquid is different from the second liquid.  
     
     
         52 . A method for focusing a charged solute in a fluid medium comprising: 
 introducing a charged solute into a fluid medium, wherein the fluid medium is contained in a device comprising 
 a first block having a first trough machined therein for receiving a fluid medium, the first trough having an inlet for introducing a first liquid to the trough and an outlet for exiting the first liquid from the trough;  
 a second block having a second trough machined therein, wherein the second block comprises an electrode array positioned in the trough, the second trough having an inlet for introducing a second liquid to the trough and an outlet for exiting the second liquid from the trough, wherein the first trough and the second trough are substantially coincident and form a channel when the first block is sealed to the second block; and  
 a porous material intermediate the first and second blocks, wherein the porous material divides the channel formed when the first block is sealed to the second block into a first chamber and a second chamber, the second chamber including the electrode array; and  
 applying an electric field gradient to the charged solute in the fluid medium to cause the charged solute to focus in a region of the medium.  
   
     
     
         53 . The method of  claim 52  wherein the first liquid is an eluant buffer.  
     
     
         54 . The method of  claim 52  wherein the second liquid is a coolant buffer.  
     
     
         55 . The method of  claim 52  wherein the first liquid is the same as the second liquid.  
     
     
         56 . The method of  claim 52  wherein the first liquid is different from the second liquid.  
     
     
         57 . A method for focusing a charged solute comprising: 
 introducing a charged solute into a fluid medium;    applying a hydrodynamic force to the solute in the fluid medium; and    opposing the hydrodynamic force with an electric field gradient to provide a solute focused in the fluid medium, wherein the electric field gradient is generated by an electrode array.    
     
     
         58 . The method of  claim 57  wherein the electrode array comprises a plurality of electrodes arranged linearly along an axis parallel to direction of migration of the charged solute in the fluid medium.  
     
     
         59 . The method of  claim 58  wherein each electrode is individually controlled.  
     
     
         60 . The method for  claim 57  wherein the electric field gradient is dynamically controlled.  
     
     
         61 . The method of  claim 57  wherein the electric field gradient is changed during the course of focusing the charged solute.  
     
     
         62 . The method of  claim 57  wherein the fluid medium comprises a chromatography support material.  
     
     
         63 . The method of  claim 57  wherein the charged solute comprises a biological solute selected from the group consisting of a protein, peptide, oligonucleotide, polynucleotide, and mixtures thereof.  
     
     
         64 . A method for separating charged solutes comprising: 
 introducing a mixture of charged solutes into a fluid medium;    applying a hydrodynamic force to the solutes in the fluid medium; and    opposing the hydrodynamic force with an electric field gradient to separate the charged solutes in order of their electrophoretic mobilities, wherein the electric field gradient is generated by an electrode array.    
     
     
         65 . The method of  claim 64  wherein each electrode is individually controlled.  
     
     
         66 . The method for  claim 65  wherein the electric field gradient is dynamically controlled.  
     
     
         67 . The method of  claim 64  wherein the electric field gradient is changed during the course of focusing the charged solute.  
     
     
         68 . The method of  claim 64  wherein the fluid medium comprises a chromatography support material.  
     
     
         69 . The method of  claim 64  wherein the charged solute comprises a biological solute selected from the group consisting of a protein, peptide, oligonucleotide, polynucleotide, and mixtures thereof.