Figure 3

Propidium iodide (PI) staining measured with microplate reader. Relative fluorescence intensity at 645 nm is shown for different live/dead proportions of S. aureus (a) and P. aeruginosa (b). Values were measured using the microplate reader after 15 minutes staining with PI of SYTO9 pre-stained cells. OD values of 0.25 for S. aureus and 0.12 for P. aeruginosa were used. Error bars represent 3 individual repeats with 3 replicas. The error bars for some data points are too small to be seen (hidden behind the symbols). Blue diamonds: mean values of the raw data; green diamonds: calculated values after subtraction SYTO9 cross-signal at 645 nm; red diamonds: values after additionally subtracting background of unbound PI.