title: Integrated capillary electrophoresis on flexible silicone microdevices:  analysis of DNA restriction fragments and detection of single DNA molecules on microchips.
abstract: Microchips for integrated capillary electrophoresis systems were produced by molding a poly(dimethylsiloxane) (PDMS) silicone elastomer against a microfabricated master. The good adhesion of the PDMS devices on clean planar surfaces allows for a simple and inexpensive generation of networks of sealed microchannels, thus removing the constraints of elaborate bonding procedures. The performance of the devices is demonstrated with both fast separations of φX-174/HaeIII DNA restriction fragments labeled with the intercalating dye YOYO-1 and fluorescently labeled peptides. Detection limits in the order of a few zeptomoles (10(-)(21) mol) have been achieved for each injected DNA fragment, corresponding to a mass detection limit of ∼2 fg for the 603 base pair fragment. Single λ-DNA molecules intercalated with YOYO-1 at a base pair-to-dye ratio of 10:1 could be detected with an uncomplicated laser-induced fluorescence detection setup. High single-molecule detection efficiency (>50%) was achieved under electrophoretically controlled mass transport conditions in PDMS microchannels.
authors.affiliation: Bioanalytical Research, Novartis Pharma AG, CH-4002 Basel, Switzerland.
authors.forename: C S
authors.initials: CS
authors.lastname: Effenhauser
authors.forename: G J
authors.initials: GJ
authors.lastname: Bruin
authors.forename: A
authors.initials: A
authors.lastname: Paulus
authors.forename: M
authors.initials: M
authors.lastname: Ehrat