Fig. 4. Confocal images of A549 cells incubated with 1 (20 μM) under different conditions. (A)–(C): cells were incubated with 1 at 37 °C (A), 25 °C (B) or 4 °C (C) for 30 min. (D) and (E): cells were preincubated with NH4Cl (50 μM) or chloroquine (10 μM) for 1 h at 37 °C and then incubated with 1 (20 μM) for 30 min, respectively. The probe was excited at 458 nm (OPM) or 810 nm (TPM). The emission was collected at 520 ± 30 nm. Overlay-OPM: overlay of the bright field and OPM columns. Overlay-TPM: overlay of the bright field and TPM columns.
