Methods and Devices for Concentration and Purification of Analytes for Chemical Analysis Including Matrix-Assisted Laser Desportion/Ionization (MALDI) Mass Spectrometry (MS)

Abstract

Analytical methods and devices are disclosed for separating low abundance analytes by electrophoretically driving the analytes through a sieving matrix to first remove high molecular weight species. Subsequently the remaining low abundance analytes are electrophoretically focused onto a capture membrane where the analytes become bound within a small capture site. After this step the capture membrane may be allowed to dry and then attached to a conductive MALDI sample plate.

1 - 38 . (canceled) 
   
   
       39 . A concentrator comprising:
 a top surface including a plurality of apertures, each aperture forming an electrolytic cell;   a capture layer having a top and a bottom and having pores that are smaller than at least one analyte of interest; and   a separation layer located between the top surface and the capture layer; wherein the capture layer captures at least one analyte of interest by sieving   
   
   
       40 . The concentrator of  claim 39  wherein the capture layer is a porous monolith. 
   
   
       41 . The concentrator of  claim 39  wherein the capture layer is a dialysis membrane. 
   
   
       42 . The concentrator of  claim 39  wherein the capture layer is porous to ionic electrical currents. 
   
   
       43 . The concentrator of  claim 42  wherein the capture layer is porous and the pores are smaller than the analyte of interest. 
   
   
       44 . The concentrator of  claim 42  wherein the capture layer pores are larger than at least a second analyte of interest wherein the capture layer has an affinity for the at least a second analyte of interest. 
   
   
       45 . The concentrator of  claim 39  including a top electrode associated with each aperture. 
   
   
       46 . The concentrator of  claim 45  including a bottom electrode associated with two or more electrolytic cells. 
   
   
       47 . The concentrator of  claim 39  wherein the separation layers are separable from the capture layer. 
   
   
       48 . A concentrator comprising:
 a top surface including a plurality of apertures, each aperture forming an electrolytic cell;   a top electrode associated with each aperture;   a capture layer having a top and a bottom and having pores that are smaller than at least one analyte of interest, the capture layer further being porous to ionic electrical currents;   a separation layer located between the top surface and the capture layer; and   a bottom electrode associated with two or more electrolytic cells, wherein the capture layer captures at least one analyte of interest by sieving   
   
   
       49 . A concentrator comprising:
 a top surface including a plurality of apertures, each aperture forming a well;   a capture layer;   a separation layer located between the top surface and the capture layer; and   a buffering layer located between a bottom electrode and the capture layer wherein the buffer layer is a continuous buffer layer that is associated with each of the plurality of apertures.   
   
   
       50 . The concentrator of  claim 49  wherein the buffering layer is selected from the group consisting of aqueous buffer layers and gel-based buffer layers. 
   
   
       51 . The concentrator of  claim 50  wherein aqueous buffering layer is a solid substrate wetted with an aqueous buffer solution. 
   
   
       52 . The concentrator of  claim 49  including a top electrode associated with each aperture. 
   
   
       53 . The concentrator of  claim 49  wherein the capture layer, separation layer and buffering layer are each porous to ionic electric currents. 
   
   
       54 . The concentrator of  claim 52  wherein the top electrodes and the bottom electrode are both non-photoresponsive electrodes. 
   
   
       55 . The concentrator of  claim 49  wherein the bottom electrode is associated with two or more of the plurality of apertures. 
   
   
       56 . The concentrator of  claim 49  wherein the buffering layer is an aqueous buffer that is incorporated into an aqueous gel or sol-gel. 
   
   
       57 . The concentrator of  claim 46  wherein the aqueous gel or sol-gel is selected from agarose, polyacrylamide and combinations thereof.