Now showing 1 - 4 of 4
  • Publication
    Microfabrication of a BioModule composed of microfluidics and digitally controlled microelectrodes for processing biomolecules
    ( 2003)
    Wagler, P.
    ;
    Tangen, U.
    ;
    Maeke, T.
    ;
    Mathis, H.P.
    ;
    McCaskill, J.S.
    This work focuses on the development of an online programmable microfluidic bioprocessing unit (BioModule) using digital logic microelectrodes for rapid pipelined selection and transfer of deoxyribonucleic acid (DNA) molecules and other charged biopolymers. The design and construction technique for this hybrid programmable biopolymer processing device is presented along with the first proof of principle functionality. The electronically controlled collection, separation and channel transfer of the biomolecules is monitored by a sensitive fluorescence set-up. This hybrid reconfigurable architecture couples electronic and biomolecular information processing via a single module combination of fluidics and electronics and opens new fields of applications not only in DNA computing and molecular diagnostics but also in applications of combinatorial chemistry and lab-on-a-chip biotechnology to the drug discovery process. Fundamentals of the design and silicon-polydimethylsiloxane (PDMS)-based construction of these electronic microfluidic devices and their functions are described as well as the experimental results.
  • Publication
    Construction of an integrated biomodule composed of microfluidics and digitally controlled microelectrodes for processing biomolecules
    ( 2003)
    Wagler, P.
    ;
    Tangen, U.
    ;
    Maeke, T.
    ;
    Mathis, H.P.
    ;
    McCaskill, J.S.
    This work focuses on the development of an online programmable microfluidic bioprocessing unit (BioModule) using digital logic microelectrodes for rapid pipelined selection and transfer of DNA molecules and other charged biopolymers. The design and construction technique for this hybrid programmable biopolymer processing device is presented along with the first proof of principle functionality. The electronically controlled collection, separation and channel transfer of the biomolecules is monitored by a sensitive fluorescence setup. This hybrid reconfigurable architecture couples electronic and biomolecular information processing via a single module combination of fluidics and electronics and opens new fields of applications not only in DNA computing and molecular diagnostics but also in applications of combinatorial chemistry and lab-on-a-chip biotechnology to the drug discovery process. Fundamentals of the design and silicon-PDMS-based construction of these electronic microfluidic devices and their functions are described as well as the experimental results.
  • Publication
    Biochemical amplification waves in a one-dimensional microflow system
    ( 2002)
    Kirner, T.
    ;
    Steen, D.
    ;
    McCaskill, J.S.
    ;
    Ackermann, J.
    A cooperatively coupled, isothermal biochemical amplification system has been investigated under flow conditions in a microstructured reactor. The experimental setup provides for continuous amplification and on line detection of the reaction products in space and time. Spatially resolved fluorescence spectroscopy with an intercalating dye was used for detection of the double stranded DNA products. Biochemical amplification was observed under a wide range of flow rates. The total rate of amplification resulted from an interplay between the amplification of the biochemical system and a loss term produced by the flow. For flow rates above a critical value, the system was diluted out and the amplification reaction brought to a halt in the reactor. Homogeneous growth throughout the reactor was observed at intermediate flow rates. At low pump rates, additional biochemical amplification started at various locations. We interpret the spatially homogeneous Growth at low concentration and the local growth at high concentration to result from two different amplification phases because of noncooperative and cooperative amplification mechanisms, respectively. The consequences for long-term evolutionary experiments as well as for complex pattern formation are discussed.
  • Publication
    Error threshold for spatially resolved evolution in the quasispecies model
    ( 2001)
    Altmeyer, S.
    ;
    McCaskill, J.S.
    The error threshold for quasispecies in 1, 2, 3, and infinity dimensions is investigated by stochastic simulation and analytically. The results show a monotonic decrease in the maximal sustainable error probability with decreasing diffusion coefficient, independently of the spatial dimension. it is thereby established that physical interactions between sequences are necessary in order for spatial effects to enhance the stabilization of biological information. The analytically tractable behavior in an infinity -dimensional (simplex) space provides a good guide to the spatial dependence of the error threshold in lower dimensional Euclidean space.