Determining the growth patterns of single cells offers answers to some of the most elusive
questions in contemporary cell biology: how cell growth is regulated and how cell size
distributions are maintained. For example, a linear growth in time implies that there is no
regulation required to maintain homeostasis; an exponential pattern indicates the opposite.
Recently, there has been great effort to measure single cells using microelectromechanical
systems technology, and several important questions have been explored. However, a …

Results To demonstrate that SLIM can recover cell growth results on a well-studied sample
(2), we imaged E. coli cells growing on an agar substrate at 37 C. The evolution of single
cells was tracked by using the Schnitzcell semiautomatic software (Michael Elowitz, Caltech;
see Materials and Methods for a detailed description).