(a) Paper strip model the electrophoresis cabinet is made to clear transparent plastic (Perspex sheet) 16" long 9 width 4 " high, effective width i.e. maximum usable width of paper carrier 7 ". The upper surface of the platform which supports the paper strip carrier and the electrode troughs are finished with black surfaces for contrast. A recessed safety inter lock switch breaks the current to both electrodes when the cabinet cover is fitted. Electrode troughs have a capacity of 550ml each and provided with two transverse baffles to minimize diffusion of buffer in electrode section of trough with buffer which is in contact with end of paper strips. The polarity of the electrode is indicated by two pilot lamps fitted with levelling screws to facilitate levelling. Supplied complete with cord and terminals connecting to the power supply, stabilised D.C. power supply unit 0-500 volts and 100 mA is provided with apparatus.