Nonlinear Electrophoretic Mobility of Large DNA Molecules in Microsystems with Sub-Micron Pillar Arrays

This paper presents a systematic study of free-solution electrophoretic motion of large DNA molecules in microsystems integrated with sub-micron pillar arrays. A nonlinear dependence of the DNA electrophoretic mobility on the applied electric field is observed. The interaction between DNA molecules and the pillar arrays is inspected under high optical magnification. Several distinct DNA molecular motions at different electric fields, associated with the DNA nonlinear response, are identified. The measured free-solution DNA mobility, inside the pillar arrays, has been found to be within the prediction range based on the Biased Reptation with Fluctuations Model.