Size-dependent free solution DNA electrophoresis in structured microfluidic systems

Thanh Tu Duong, Gyuman Kim, Robert Ros, Martin Streek, Friederike Schmid, J. ürgen Brugger, Dario Anselmetti, Alexandra Ros

Research output: Contribution to journalConference articlepeer-review

54 Scopus citations


A new concept based on microstructuring techniques is presented to achieve size-dependent electrophoretic migration of DNA in free solution. Topographically structured microfluidic channels with periodical cavities in the range of the radius of gyration of the tested DNA molecules (<3 μm) are produced by moulding of polydimethylsiloxane on a master wafer fabricated by contact lithography of SU-8 photoresist. The electrophoretic migration of single DNA molecules stained with the intercalator YOYO was investigated by real-time fluorescence video microscopy. It could be demonstrated for large DNA molecules that λ-DNA (48 kbp) always migrated significantly faster than T2-DNA (164 kbp) in the two tested microchannel layouts. Integration into a microdevice for DNA separation in free solution is now in progress.

Original languageEnglish (US)
Pages (from-to)905-912
Number of pages8
JournalMicroelectronic Engineering
StatePublished - Jun 2003
Externally publishedYes
EventProceedings of the 28th International Conference on MNE - Lugano, Switzerland
Duration: Sep 16 2002Sep 19 2002


  • Contact lithography
  • DNA
  • Electrophoresis
  • Fluorescence microscopy
  • Microchip
  • Single molecule

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering


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