(136b) Influence of Pore Morphology on DNA Separation Performance In Microchip Gel Electrophoresis

Gel electrophoresis is an essential analytical step in a wide range of DNA analysis assays. Incredible progress continues to be made toward adapting electrophoresis technology for use in portable low-cost applications, but miniaturization demands increasingly precise control over all aspects of the process in order for separations to be performed in ultra-short distances. Here we explore the role of the sieving gel's nanoscale pore morphology in directing DNA migration during electrophoresis. We accomplish this by harnessing a unique combination of methods that enable both the mean pore size and the pore size distribution of the gel to be quantitatively characterized, and a versatile microfluidic platform that allows the progress of DNA separations to be continuously monitored along the entire microchannel in near real time. This approach allows us to identify how polymerization conditions (i.e., UV intensity during photopolymerization) influence the gel pore size distribution, and ultimately shape overall separation performance. Analysis of double-stranded DNA separations in the size range below 1 kb reveals that varying the rate of photopolymerization induces a corresponding change in the physical mechanism of DNA migration between reptation and entropic trapping. These results highlight the direct link between polymerization conditions, gel pore morphology, and DNA separation performance. We hope these measurements can help provide new insights into the interplay between the nanoporous architecture of the gel matrix and the electrophoretic transport process.