Lysis of the growing cells with ampicillin. The stationary phase cells containing GFP were diluted into fresh medium. After 2 hours of growth, ampicillin was added (zero time) and samples were taken at times indicated (B). An untreated culture was used as a control (A). The samples where analyzed by flow cytometry. Growing cells (high side scatter and low amount of GFP) are indicated in green, nongrowing cells (low side scatter and high amount of GFP) are indicated in blue, a population of debris particles in the flow buffer is indicated in black.