Circuit for clamping voltages at the electrodes inside CHEF chambers of pulsed field gel electrophoresis systems

A circuit for imposing voltages on the electrodes of trays used in a CHEF pulsed field electrophoresis system is formed by two identical application circuits that are connected to a power source by an alternator in such a way that only one of the two circuits receives electrical energy each time. Each application circuit comprises several resistors and diodes, which are series connected to form a voltage divider. Voltage repeaters are connected to the nodes formed at the union of two resistors. Each repeater is connected to a pair of electrodes that are to be polarized to the same potential. Diodes are introduced to correct minor errors in the voltage pattern applied to the electrodes. The circuit can maintain the potential in each electrode when conductivity variations occur during electrophoresis. Each application circuit generates a homogeneous electrical field having the same value and different direction in a tray used in the CHEF pulsed field electrophoresis system.