Abstract: A microchip device includes a focusing channel, in which an electric field strength established in the focusing channel is controlled relative to an electric field strength established in a material transport channel segment to spatially focus the material traversing the material transport channel segment.

Abstract: A user programmable device for horizontal gel eletrophoresis is provided. This device can both accurately and programmably control: (a) the angle between electrical field and gel by use of a rotatable gel bed, (b) magnitude of the electrical field, and (c) temperature. The present invention is programmable by a microprocessor-based contol board which sends control signals to: (a) a motor attached to the rotatable gel (b) the source of elecrical potential and (c) Peltier devices attached to the sides of buffer chambers horizontally displaced from the rotatable gel bed. The present invention is particularly appropriate for lowering cost, lowering footprint, reducing heat dissipated, maintaining close tolerances of electric field gradients and temperature, and exploring and using thus far untried modes of electrical field variation. It is thereby suitable for analyzing large linear DNA, open circular DNA and/or DNA-protein complexes.