Capillary-zone electrophoresis in agarose gels using absorption imaging detection

A simple home-built electrophoretic unit and a commercially available charge-coupled device (CCD) camera with image acquisition and analysis software were used to study the separation process in zone electrophoresis experiments in 4 cm long, round capillaries (inside diameter 0.2 mm). Several capillaries could be investigated simultaneously. The absorption imaging system was used not only to follow the course of the separation but also to study the interaction between biologically active substances (proteins, detergents, enzymes and-substrate). Since the system allows visual on-line observation of the separation one can rapidly decide when the analysis is finished, which often shortens the analysis time. The electrophoresis method presented is suitable also for preparative runs, since direct visualizations of a solute zone allows it to be excised and then used for further studies.