Screening of mitophagy regulators for removing damaged mtDNA. HeLa cells were infected by lentiviral particles containing the indicated knockdown vectors. Five days later, cells were treated with 200 µM H2O2 for 2 h. Cells were then imaged with 458 nm (measuring mitochondria with a neutral pH) and 561 nm (measuring mitochondria with an acidic pH) laser excitation for mito-Keima. ShATG5 was used as a negative control. Right panels for each image show the FACS-based mito-Keima dot plots. The y-axis represents the fluorescence emission of mito-Keima at pH 4.0 (lysosome), while the x-axis indicates mito-Keima at pH 7.0 (mitochondria). The percentages of cells within the different regions are indicated. Scale bar, 10 µm. 