Figure 3.

The analysis of fluorescent F105 analogue (F145) penetration into planktonic bacterial cells. Gram-positive (S. aureus and B. cereus) and Gram-negative (S. marcescens and K. pneumonia) bacteria were grown for 24 h with agitation in MH broth, then washed and resuspended in PBS. F145 was added until the final concentration of 10 μg/mL (close to MIC of F105 for Gram-positive bacteria), and incubation was followed for the next 15 min. Then, the cells were live/dead stained with DioC₆/PI (additional 15 min) and analyzed with confocal laser scanning microscopy. Images show the fluorescence of DioC₆ (a), PI (b), F145 (c) and the combination of all channels (d). The scale bars indicate 2.5 µm.