Jia Ou1, Daniel Olson1, Michael Meloche2, and Kevin D. Dorfman1. (1) Department of Chemical Engineering and Materials Science, University of Minnesota, 151 Amundson Hall, 421 Washington Ave SE, Minneapolis, MN 55455, (2) Department of Biomedical Engineering, University of Minnesota, 151 Amundson Hall, 421 Washington Ave SE, Minneapolis, MN 55455
The separation of long DNA by electrophoresis through regular arrays of micropillars is a major accomplishment of microfluidics, with the potential of reducing day-long macroscale separations into the minute range. We will present new experimental data obtained for the transport properties of lambda-phage DNA (48,500 base pairs) in model post arrays. The devices are fabricated in PDMS, featuring centimeter-long hexagonal arrays of 1 micron posts with pitches of 3, 5 and 7 microns. We have implemented a robust method for fabricating and preparing these chips that allows for high chip-to-chip reproducibility and reusability. We will present results on the mobility and dispersivity of lambda-DNA as a function of the pitch of the array and the electric field. These data will be compared with prevailing theories of DNA electrophoresis, including continuous-time random walk predictions and the so-called “channeling” effect that is predicted by simulations of DNA electrophoresis in sparse, ordered arrays.