DNA analysis on electrophoretic microchips: Effect of operational variables

Applicability of modern microfabrication technology to electrophoresis micr ochips initiated a rapidly moving interdisciplinary field in analytical che mistry. Electric field mediated separations in microfabricated devices (ele ctrophoresis microchips) are significantly faster than conventional gel ele ctrophoresis, usually completed in seconds to minutes. Electrophoretic sepa ration of DNA molecules on microfabricated devices proved to have the poten tial to improve the throughput of analysis by orders of magnitude. The flex ibility of electrophoresis microchips allows the use of a plethora of separ ation matrices and conditions. In this paper, we report on electric field m ediated separation of fluorescent intercalator-labeled dsDNA fragments in p olyvinylpyrrolidone matrix-filled microchannel structures. The separations were detected in real time by a confocal, single-point laser-induced fluore scence/photomultiplier setup. Effects of the sieving matrix concentration ( Ferguson plot), migration characteristics (reptation plot), separation temp erature (Arrhenius plot), as well as applied electric field strength and in tercalator concentration on the separation of DNA fragments are thoroughly discussed.