Abstract: An electrodialysis fluid purification device includes a fluid output from an upper part of a first fluid reservoir. One or more ion permselective elements at a surface on or near the bottom of the first reservoir are arranged to provide one or more small area points or lines. A fluid connection to a second fluid reservoir is on an opposite side of the one or more ion permselective elements. Electrodes and a power supply create a voltage differential across the one or more ion permselective elements. Another fluid purification device includes a first reservoir with which an ion permselective element interfaces directly in a 2D to 3D relationship. A method employs small area ion permselective element interfaces at a surface on or near the bottom of the first reservoir such that ion transport creates a depleted zone that extends into the first fluid reservoir.

Abstract: An electrokinetic purification device includes at least three channels and a turbulence-reduction component for reducing turbulence with the concentration polarization (CP) zone. The main channel includes a pair of electrodes in contact with a solvent stream entering and exiting the main channel. A waste diversion channel branches from the main channel, allowing flow-through of a high concentration portion of the stream. A turbulence-reduction component comprised of a neutrally charged porous is placed across the entire interior cross section of the main channel and in contact with the upstream surface of the permselective material. The clean solvent discharge channel branches from the main channel, allowing flow-through of a low concentration portion of the stream.

Abstract: A continuous periodic electric wave electrophoresis device and method generates a continuous periodic electric wave that electrophoretically separates charged particles within a sample. The device can have a channel wherein the sample is introduced. At least three interdigitated arrays of conducting electrodes can be positioned adjacent the channel with each array having an externally controllable electrical potential. An externally controlled electric current can be applied to each array of conducting electrodes, creating a continuous periodic electric wave having a selectable wave speed within the channel that separates the particles within the sample. The continuous periodic electric wave can entrain high-mobility particles and immobilize low-mobility particles.

Abstract: The present invention provides a microfluidic device capable of reacting an enzyme or other agent with a substantially purified polypeptide. In one embodiment of the present invention, the microfluic device comprises a plurality of reaction channels wherein the substantially purified polypeptide is delivered to a reaction channel. Once confined within the reaction channel, the substantially purified polypeptide engages the enzyme or agent and produces a reaction product. In a preferred embodiment of the present invention, the reaction product is concentrated at a charged membrane prior to being removed from the microfluidic device. Additionally, the present invention provides a method of concentrating a positive analyte at a positively charged membrane and a negative analyte at a negatively charged membrane. Once concentrated, the analytes may be removed from the microfluidic device.

Abstract: An apparatus and method for Edman degradation using a microfluidic system to identify and characterize peptides is disclosed. A microfluidic device comprises an entrance channel through which a substantially purified polypeptide is accepted, a reaction channel engaging the entrance channel wherein the substantially purified polypeptide is digested, producing a digestion product, a reagent reservoir engaging the reaction channel, the reagent reservoir capable of delivering a reagent to the reaction channel, and an exit channel extending from the reaction channel, wherein the digestion product travels through the exit channel upon leaving the reaction channel.

Abstract: The present invention provides an apparatus and method of utilizing bi-directional capillary electrophoresis (“CE”) device. In one embodiment, cations are drawn into a first uncharged channel towards a negative electrode and anions are drawn into a second uncharged channel towards a positive electrode. The uncharged channels allows for minimal interaction between the sample and the walls of the channel which allows for minimal sample loss. The present invention also provides a method of separating anions from cations. The method comprises delivering the mixture to a bi-directional CE device. Following delivery, cations are drawn into a first uncharged channel towards a negative electrode and anions are drawn into a second uncharged channel towards a positive electrode. In one aspect of the present invention, the bi-directional CE device engages a microfluidic proteome analysis system.

Abstract: The invention provides a microfluidic system and method to rapidly analyze large numbers of compounds or complex mixtures of compounds, particularly, low abundance cellular proteins involved in cell signaling pathways. In one aspect, an integrated microfluidic system comprises an upstream separation module (preferably, a multi-dimensional separation device), a microfluidic device for on-device protein digestion of substantially separated proteins received from the upstream separation module, a downstream separation module for separating digestion products of said proteins, a peptide analysis module and a processor for determining the amino acid sequence of said proteins. Preferably, the system comprises an interfacing microfluidic device between the downstream separation module and the peptide analysis module.