Figure 4.

The fraction of propidium iodide (PI) and Syto9 stained cells in an E. coli culture sampled by fast filtration under controlled vacuum with and without a quick warm (37 °C) water rinse on the filter, as estimated by fluorescence microscopy imagining. The average ± SD of n = 3 technical replicates is presented. >3000 cells were counted per technical replicate. Significance levels from two-tailed t-tests assuming equal variances are marked ns: not significant.