(101a) The Effect of Disorder On DNA Dynamics In Post Arrays During Electrophoresis

Short DNA (<10 kbp) is commonly separated by size during electrophoresis in disordered, self-assembled gels with pore sizes on the order of 200 nm.  Long DNA (~50 kbp) can be separated by a dc electric field when the pore size is several microns.  Indeed, separations have been shown in both highly ordered microfabricated post arrays and in disordered quasi-hexagonal matrices of self-assembled magnetic beads.  While there have been studies of single molecule dynamics in ordered and disordered systems, the role of disorder is unknown.  To study how the disorder in geometry affects DNA separation, we use top-down fabrication techniques to create post arrays with varying degrees of disorder.  Using fluorescent microscopy we examine the dynamics of single DNA molecules in these arrays.  Additionally, we automate stage motion during experiments to follow single molecules over large distances.  We will present data on the probability distributions for the holdup time and distance in arrays of different disorder and compare our results to the existing theories for these devices.