Figure 1.

Co-localization of C-1330 and LysoTracker red in lysosomes in A549 and A549/K1.5 cells. Parental A549 (a–c) and their MDR subline A549/K1.5 (d–f) were viably stained with Hoechst 33342 (blue nuclear fluorescence) along with either 100 nM LysoTracker red for 1 h (red fluorescence; a, and d) or 10 μM C-1330 (green fluorescence; b, and e) for 30 min. Viable cell staining and quantification of the number of red fluorescent lysosomes per cell were carried out by first staining with 100 nM LysoTracker red for 1 h (g) followed by lysosome counting in at least 25 cells from each of three independent experiments using the EZ-Quant software. Inverted fluorescence microscopy analysis of viable cell staining was performed at a magnification of × 630