Abstract: A method and device are provided for affinity gradient focusing for directing at least one analyte in a solution containing a pseudostationary phase and located in a channel such as a capillary or a microchannel. The method includes establishing a steady-state spatial gradient in a retention factor of the pseudostationary phase for the at least one analyte. The analyte is caused to be moved within the channel whereby the concentration of the at least one analyte changes at one or more positions along the gradient. The pseudostationary phase is charged and the analyte is either neutral or charged or alternatively, the pseudostationary phase is neutral and the analyte is charged. The device may include a fluid channel, a pseudostationary phase having a retention factor gradient, an electrical current source and a pump system for establishing the bulk flow in the solution in the channel.

Abstract: A described exemplary embodiment of the present invention includes a computational “toolbox” for the a priori design of optimized fluidic components. These components consist of a channel under low-Reynolds number, pressure-driven flow, with an arrangement of grooves cut into the top and/or bottom to generate a tailored cross-channel flow. An advection map for each feature (i.e., groove of a particular shape and orientation) predicts the lateral transport of fluid within the channel due to that feature. We show that applying these maps in sequence generates an excellent representation of the outflow distribution for complex designs that combine these basic features. The effect of the complex three-dimensional flow field can therefore be predicted without solving the governing flow equations through the composite geometry, and the resulting distribution of fluids in the channel is used to evaluate how well a component performs a specified task.

Abstract: A method and device are provided for affinity gradient focusing for directing at least one analyte in a solution containing a pseudostationary phase and located in a channel such as a capillary or a microchannel. The method includes establishing a steady-state spatial gradient in a retention factor of the pseudostationary phase for the at least one analyte. The analyte is caused to be moved within the channel whereby the concentration of the at least one analyte changes at one or more positions along the gradient. The pseudostationary phase is charged and the analyte is either neutral or charged or alternatively, the pseudostationary phase is neutral and the analyte is charged. The device may include a fluid channel, a pseudostationary phase having a retention factor gradient, an electrical current source and a pump system for establishing the bulk flow in the solution in the channel.