Apparatus and method for trapping bead based reagents within microfluidic analysis systems

Abstract

An on-chip packed reactor bed design is disclosed that allows for an effective exchange of packing materials such as beads at a miniaturized level. Also disclosed is a method of treating a sample within a microfluidic analysis system, comprising; providing a main channel having a trapping zone; providing a slurry of a reagent treated packing material; inducing a flow of said packing material into said trapping zone through a flow channel connected to said trapping zone to load said trapping zone and form a packed bed of said packing material; and flowing a sample containing analytes through said packed bed, said reagent treating the sample. The present invention extends the function of microfluidic analysis systems to new applications including on-chip solid phase extraction (SPE) and on-chip capillary electrochromatography (CEC). The design can be further extended to include integrated packed bed immuno- or enzyme reactors.

1 - 39 . (canceled) 
     
     
         40 . A method comprising:
 a) providing particles susceptible to a magnetic field; and   b) trapping said particles with a magnetic field in a chamber of a microfluidic device.   
     
     
         41 . The method of  claim 40  further comprising flowing the particles into the chamber through a microfluidic channel. 
     
     
         42 . The method of  claim 40  further comprising:
 c) removing the particles from the chamber. 
 
     
     
         43 . The method of  claim 40 ,  41  or  42  wherein an analyte is retained by the particles and the method further comprises eluting the analyte off the particles in the chamber. 
     
     
         44 . The method of  claim 43  further comprising washing the particles prior to eluting the analyte. 
     
     
         45 . The method of  claim 40  wherein the particles comprise beads. 
     
     
         46 . The method of  claim 45  wherein the beads are spheroid. 
     
     
         47 . A method comprising:
 a) providing a microfluidic device comprising a microfluidic channel and a chamber;   b) moving a solid phase separation component through the microfluidic channel into the chamber;   b) trapping the solid phase separation component in the chamber, wherein the solid phase separation component comprises a retained analyte captured from a sample; and   c) washing the solid phase separation component in the chamber to remove impurities.   
     
     
         48 . The method of  claim 47  further comprising:
 d) eluting the analyte from the solid phase separation component. 
 
     
     
         49 . The method of  claim 47  wherein the solid phase separation component is trapped using a magnetic field. 
     
     
         50 . The method of  claim 47  wherein the analyte has higher concentration in the eluant than in the sample. 
     
     
         51 . The method of  claim 47  further comprising:
 d) removing the magnetic material from the chamber. 
 
     
     
         52 . The method of  claim 51  wherein the solid phase separation component comprises beads. 
     
     
         53 . The method of  claim 45  wherein the beads are spheroid. 
     
     
         54 . A method comprising:
 a) providing a microfluidic device comprising a main channel having a trapping zone suitable for trapping a solid phase separation component;   b) flowing a solid phase separation component into the trapping zone; and   c) flowing the solid phase separation component out of the trapping zone.   
     
     
         55 . The method of  claim 54  wherein the solid phase separation component in the trapping zone comprises a retained analyte captured from a sample. 
     
     
         56 . The method of  claim 54  wherein the solid phase separation component comprises beads. 
     
     
         57 . The method of  claim 56  wherein the beads are spheroid.