Figure 7. Intracellular pH measurements using Superior LysoProbe (IV) (1 μM) in ARPE cells: After washing three times with corresponding pH buffers, cells were further incubated with nigericin and then imaged in buffers maintained at: (A) pH 4.0; (B) pH 4.5; (C) pH 5.0; and (D) pH 7.4.

Cells were imaged on an inverted laser scanning fluorescent microscope (Olympus) using a 60 × oil immersion objective lens.