The present invention provides a method for the electrophoretic separation
of particles, especially of macromolecules, comprising the steps of
applying the particles to be separated on a substrate supported membrane,
such that the particles are mobile across the surface of the substrate
supported membrane; providing an electrical field such that electrical
fields are formed along the surface across which the particles are
mobile; and temporarily modifying the electrical field and/or adding a
substrate supported membrane having a structured surface, wherein the
direction and/or the strength of the electrical field are temporarily
modified and/or wherein the substrate supported membrane is structured so
that a force is acting on the particles that leads to a movement
depending on the length of the particles. Moreover, a substrate is
provided, in particular, for supporting a membrane during the performing
of the inventive methods, that comprises an optically transparent
material. Moreover, the invention provides a substrate supported membrane
for carrying out the inventive methods including an inventive substrate
as defined in the claims and a fluid lipid membrane. Moreover, the
present invention provides a microchannel electrophoresis chamber having
at least one channel with a bottom surface including an inventive
substrate, and an electrode assembly.