Chairperson, Graduate Committee: Abigail Richards; Connie Chang (co-chair)Lindsay, Travis Carson2023-10-182023-10-182023https://scholarworks.montana.edu/handle/1/17876Bacteria can survive antibiotic or bactericidal treatment through genetic mutations. Even within bacterial populations that are fully susceptible to treatment, a small proportion of cells can have enhanced survival capacity in a phenomenon called persistence. Traditional microbiology methods can fail to identify or isolate these persister cells present within the population. A novel method for high-throughput single cell analyses of microbial populations is that of drop-based microfluidics, in which individual cells can be isolated within picoliter-sized drops. In this work, fluorescent detection and dielectrophoresis-based sorting of drops was developed for isolating Pseudomonas syringae persister cells following antimicrobial treatment. We demonstrate: (1) the dielectrophoresis-based sorting of dye-filled 25 micron drops based upon two colors, (2) differences between laser-induced fluorescent detection of dyes compared to single bacterial cells, (3) single-cell isolation of P. syringae into 25 micron droplets with ~10% of droplets containing singlecells, and (4) the treatment, staining, and fluorescent characterization of P. syringae at 0.5x, 5x, and 50x the minimum inhibitory concentration of carbonyl cyanide m-chlorophenyl hydrazone (CCCP), an antibiotic which resulted in 6.2%, 10.2%, and 88.6% cell death of the population, respectively. These results provide the groundwork for studying antibiotic-treated P. syringae and the isolation of surviving cells that will lend insight into the molecular basis of persistence for preventing recurrent infections and decreasing the likelihood of antibiotic resistance.enPseudomonasMicrofluidicsCultures (Biology)ElectrophoresisFluorescenceThesisCopyright 2023 by Travis Carson Lindsay