This invited Book Chapter, written by my colleague Emma Dawson and edited by myself, describes methodologies that I either developed or adapted for my Ph. D. dissertation research.

Evading an antibiotic treatment by transiently non-growing is called bacterial persistence. This phenomenon reflects to bacterial population time-kill curves as a long-tail or virtually a plateau at long times. Previous single-cell studies observed persister cells. Past population-level measurements suggested a double-exponential dynamics for the time-kill curves with a slow phase describing the death kinetics of persisters preceded by a fast phase representing the death of other normal cells. In this study, by measuring the time length of no-growth (lag time) for ~13 000 single cells with microscopic observations, we unveil that the slow phase is actually not quite exponential, but rather is more close to a power-law decay. By mathematical arguments we show that such a power-law decay can emerge from many simultaneous random (Poisson) processes. Notably, this interpretation can embrace practically an infinite number of underlying molecular mechanisms. This is consistent with an already myriad mechanisms of persistence that have been reported to date.