Pressure-Induced Flow and Resultant Orientation of Polyacrylamide Chains Impacts Peak Width in DNA Sequencing Separatoins in Microchannel Electrophoresis

For years, microchannel electrophoresis has provided high-resolution separations of DNA, which in turn has lead to highly accurate sequencing data. Initially, microchannel electrophoresis was performed on a capillary array electrophoresis (CAE) platform. As the need to increase throughput has risen, much work has been done to transition from the CAE platform to a microchip electrophoresis platform. While microchip electrophoresis offers faster separation times, this technology has yet to offer the consistent long-reads of CAE. Previous work in our lab has shown differences in separation performance between CAE and microchip electrophoresis for the same replaceable polymer network; namely the separation efficiency greatly decreases in microchips. To better understand DNA migration in microchip, we looked at the apparent dispersion coefficient of DNA for a number of different linear polyacrylamides and poly(N,N-dimethylacrylamides) polymer networks to determine the extent of band broadening. In this study, the physical properties of linear polyacrylamide networks were found to influence band broadening in a time-dependent fashion. Ultimately, understanding the relationship between the physical properties of the polymer network and band broadening will result in increased read lengths on the microchip platform.