Fig. 3. Co-localization of A. fumigatus conidia with acidic organelles in A549 and J774 cells. (A) A549 cells were incubated with A. fumigatus conidia for 6 (a) or 24 hours (b). J774 cells were incubated with A. fumigatus conidia for 6 hours (c). Following incubation times, cells were incubated with pre-warmed LysoTracker for 30 minutes and then unfixed cells were directly viewed on the confocal microscope. From left to right: fluorescence image showing the green channel (conidia), fluorescence image of the red channel (endosomes/lysosomes) and a merged overlay of both images. Bars, 10 µm. (B) The percentage of A. fumigatus phagosomes that co-localized with the LysoTracker probe was scored by analysis of at least 100 conidia in three separate experiments, each represented by a different symbol (circles, squares or diamonds).