Kinetics of thymineless death in Escherichia coli 15 as measured by single-cell observations.

Kinetics of thymineless death for Escherichia coli 15 TAU-bar from plating on solid medium were compared with those from direct observations of single cells under a microscope. The latter method did not involve any physical change of the medium. The kinetics obtained for the two methods were identical. This rules out the assumption that in E. coli 15 TAU-bar death from the thymine deprivation is directly associated with the plating procedure.