Observing Bacterial Persistence at Single-Cell Resolution.

Within a bacterial population, there can be a subpopulation of cells with an antibiotic-tolerant persister phenotype characterized by long lag phase. Their long lag phase necessitates long (hours or days) periods of single-cell observation to capture high-quality quantitative information about persistence. We describe a method of single-cell imaging using glass bottom dishes and a nutrient agarose pad that allows for long-term single-cell microscopy observation in a stable environment. We apply this method to characterize the lag phase and persistence of individual Escherichia coli cells.