Switching characteristics of single cells at 30 µg/ml bacitracin.

<p>Fluorescence development of single cells over time at 30 µg/ml bacitracin was comparable to the data obtained by single cell analysis of the above described population study: All cells switched into the induced ‘ON’ state, exceeding the threshold fluorescence intensity within 15 min. In contrast to the whole population study the maximal fluorescence intensity was reached only after 80 min. A) Fluorescence development of one individual cell is shown. Top: bright field images at different time points. Bottom: fluorescence images at different time points. B) Fluorescence development of 13 individual cells is shown. C) Sigmoidal fits have been applied to eight fluorescence intensity traces in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053457#pone-0053457-g006" target="_blank">Figure 6B</a>. The fluorescence intensity was normalized to the maximum fluorescence intensity and the time axis was shifted to T₄₅, where cells had half-maximum fluorescence intensity. Blue and red line: two individual fluorescence traces representing cells with the slowest and highest individual switching rates in this cell batch.