Versatile 3-channel high-voltage power supply for microchip capillary electrophoresis

The fabrication of a battery operated 3-channel high voltage power supply for microchip capillary electrophoresis is described. The power supply consists of two positive and one negative DC–DC converters, a microprocessor controlled timer, a battery and a transformer to recharge the battery and feed the high voltage relays. This arrangement allows the possibility to control the potentials applied in the 0 to ±4000 V range to a variety of microchip setups. It can also be easily adapted to perform either gated or pinched injection. The inclusion of a rechargeable battery was adopted to feed the DC–DC converters to reduce noise levels and achieve portability.