Towards a miniaturised system for dynamic field gradient focused separation of proteins

Separation and focusing of proteins is described in a miniaturised dynamic field gradient focusing device with a 2.5 cm × 0.1 cm channel filled with a porous polymer monolith. The separation channel is in contact with a parallel electric field channel with five individually addressable electrodes through a porous glass membrane so that a variable field can be generated that drives charged proteins electroosmotically against a constant hydrodynamic flow. Separated pre-stained proteins were detected by means of a digital camera and background subtraction.