Sentence:  These include low-temperature ethanol ( Cohn ) fractionation , <WSD>electrophoresis</WSD> , ultracentrifugation and column chromatography on ion exchange celluloses . 
Meaning of the word marked with <WSD> tags:  the motion of charged particles in a colloid under the influence of an electric field; particles with a positive charge go to the cathode and negative to the anode