Figure S1.

The relationship between the number of colony-forming units (CFUs) per well and counts per second (cps) of bioluminescence intensity. CFUs were measured by plating for single colonies at various time points during exponential growth (black) and at the end of exponential growth (gray). The linear fit corresponds to 30 CFUs per well per cps. This linear relationship holds throughout four orders of magnitude of exponential growth; it breaks only at high cell densities, when the population enters stationary phase.