Fig. 3
Fluorescence imaging of intracellular viscosity or pH changes by HFI. A Fluorescence images of HeLa cells pretreated with HFI (10 μM) for 30 min and then incubated with monensin (10 μM) or nystatin (10 μM) for another 30 min. B Relative fluorescence intensity for A. C Fluorescence images of HFI (10 μM) stained HeLa cells in pH 3.0, 4.0, 5.0, 6.0, and 7.0, respectively. D Relative fluorescence intensity for C. E The intensity ratio of the red channel to the blue channel at different pH values. Blue channel: λem = 460 ± 20 nm, λex = 405 nm. Red channel: λem = 610 ± 20 nm, λex = 405 nm. Scale bar, 10 μm