Electrophoresis is the motion of
dispersed particles relative to a fluid under the influence of a spatially uniform
electric field. This
electrokinetic phenomenon was observed for the first time in 1807 by Ferdinand Frederic Reuss (
Moscow State University), who noticed that the application of a constant
electric field caused
clay particles dispersed in
water to migrate. It is ultimately caused by the presence of a charged interface between the particle surface and the surrounding fluid. It is the basis for a number of analytical techniques used in biochemistry for separating molecules by size, charge, or binding affinity.