2.8. Immunofluorescence assay

Human malignant mesothelioma cells were seeded in 8‐well chamber slides (SPL Life Sciences, Pocheon, Korea) and incubated with MitoTracker Deep Red (Molecular Probes, Eugene, OR, USA) for 30 minutes in the dark. Fixation, permeabilization and blocking were carried out using 4% paraformaldehyde (Millipore), 0.1% Triton X‐100 (Amresco, Solon, OH, USA) and blocking solution (BSA 3% in PBS with 0.1% Tween‐20 [PBST]) for 15, 10 and 30 minutes, respectively. After washing with PBS, Mdr1 antibody was added in blocking solution and incubated overnight at 4°C. Subsequently, the Alexa Fluor 488‐conjugated anti–mouse secondary antibody (Molecular Probes) was added in blocking solution and incubated for 2 hours in the dark. In addition, nuclear was stained using DAPI (Molecular Probes). Fluorescence images were captured using an LSM710 confocal laser scanning microscope (CLSM; Carl Zeiss, Göttingen, Germany) and analyzed using LAS AF Lite software (Leica, Wetzlar, Germany).