Software automated genomic engineering (SAGE) enabled by electrowetting-on-dielectric digital microfluidics
Software automated genomic engineering (SAGE) enables arbitrary genetic modification of bacteria on a fluidic platform that implements the multiplex automated genomic engineering (MAGE) process [1]. Electrowetting-ondielectric (EWD) digital microfluidics is well suited for SAGE because of its inherent reconfigurability, small reagent volumes, and parallel processing capability [2]. We report on the first demonstration of bulk cell transformation of E. coli by an electroporation device integrated with an EWD microfluidics system, which achieved up to 9.8% transformation efficiency (evaluated as the ratio of transformed cells to survived cells) while maintaining fluid transport capability. Toward the goal of enabling efficient MAGE cycling with real time feedback control, monitoring of cell recovery and growth was implemented via reflectance spectroscopy with a limit of detection of about 108 cells/ml. Furthermore, simulated MAGE cycles showed that bacteria remained viable for at least 90 cycles (27 days) on-chip.