An apparatus for performing gel electrophoresis using a plurality of cassette sockets that can accommodate a plurality of gel cassettes. The apparatus allows each gel cassette to be run concurrently and individually. In accordance to the suggested enhancements, different gel compositions and different liquid buffer solutions could be used simultaneously. The apparatus also permits a group of users to use the same apparatus at the same time for distinctive experiments. The electric current for each cassette can be switched on or off at any time without disturbing the progress in other subunits. A heat exchanger within the apparatus comprises of tubes that carry the coolant into the apparatus through an inlet and out through an outlet.
