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