Oscillation of DnaA-YFP^sw in <i>E</i>. <i>coli</i>.

<p>Fluorescence microscopy images of <i>E</i>. <i>coli</i> cells, A) expressing DnaA-YFP^sw during exponential growth, B) 60 min after the addition of 200 μg/ml rifampicin, C) <i>B</i>. <i>subtilis</i> cells expressing TetR-YFP binding to a <i>tetO</i> array near <i>oriC</i>. Fluorescence intensities of two areas, each containing one fluorescence signal, were measured and normalized to the total fluorescence intensity of the cell. Intensities of both areas were plotted over time. Area 1 (black) and area 2 (white). Image sequences displaying the oscillation of DnaA-YFP^sw (A–B) and the static TetR-YFP (C) are shown. White lines, cell borders; scale bars, 2 μm; white dashed lines, cell outlines; black open circle, area 1; green open circle; area 2. To visualize the correlation between the two measured areas they were plotted against each other (D–F). Correlation coefficients (r) were determined.