Devices and methods for sample characterization

Abstract

Devices and methods for characterization of analyte mixtures are provided. Some methods described herein include performing enrichment steps on a device before expelling enriched analyte fractions from the device for subsequent analysis. Also included are devices for performing these enrichment steps.

1 - 33 . (canceled) 
     
     
         34 . A microfluidic device comprising:
 a least one inlet,   a first fluid channel, wherein the at least one inlet is configured to introduce an analyte mixture on to the first fluid channel,   an orifice in fluid communication with the first fluid channel,   a second fluid channel in fluid communication with the first fluid channel,   at least one gas delivery channel, and   a transparent portion, wherein the transparent portion is configured to allowing imaging of the analyte mixture.   
     
     
         35 . The microfluidic device of  claim 34 , wherein the first fluid channel is a separation channel. 
     
     
         36 . The microfluidic device of  claim 34 , further comprising a power supply, wherein the power supply is configured to apply an electric field to the first fluid channel. 
     
     
         37 . The microfluidic device of  claim 36 , wherein the application of a first electrical field effects a separation of the analyte mixture via isoelectric focusing. 
     
     
         38 . The microfluidic device of  claim 37 , where the transparent portion is configured to allow imaging of the separation of the analyte mixture. 
     
     
         39 . The microfluidic device of  claim 37 , where the transparent portion is configured to allow imaging of the focused analyte mixture. 
     
     
         40 . The microfluidic device of  claim 37 , wherein the application of a second electrical field or pressure mobilizes the separated analytes. 
     
     
         41 . The microfluidic device of  claim 40 , where the transparent portion is configured to allow imaging of the mobilization of the analyte mixture. 
     
     
         42 . The microfluidic device of  claim 34 , wherein the second fluid channel is configured to introduce an electrolyte into a separated analyte mixture. 
     
     
         43 . The microfluidic device of  claim 34 , wherein the second fluid channel is in fluid communication with a confluence region downstream of the first fluid channel. 
     
     
         44 . The microfluidic device of  claim 34 , wherein the first fluid channel and the second fluid channel intersect at a confluence region. 
     
     
         45 . The microfluidic device of  claim 44 , the confluence region is in an electric field of the first fluid channel. 
     
     
         46 . The microfluidic device of  claim 44 , wherein the confluence region is in line with the first fluid channel and the orifice. 
     
     
         47 . The microfluidic device of  claim 40 , wherein separated and mobilized analytes are expelled from the orifice via electrospray ionization. 
     
     
         48 . The microfluidic device of  claim 47 , wherein the at least one gas delivery channel is configured to facilitate the electrospray ionization.