*4.11. Cell Proliferation Assay*

Cell proliferation was measured using Quick Cell Proliferation Assay Kit (Abcam, Cambridge, MA, USA) following manufacturer's protocol. This assay is based on cleavage of tetrazolium salt (WST-1) to formazan by mitochondrial dehydrogenases. EVC, AKI, and BKI iOTR cells were plated to a density of 1000 cells/100 µL in 96-well tissue culture plates, with four replicates of each cell type. After 4, 24, 48, or 96 h of plating the cells, 10 µL WST-1 reagent was added in each well followed by incubation for 2 h in standard culture conditions. Absorbance was measured using Cytation 3 Multi-Mode Reader (BioTek Instruments, Inc., VT, USA) at 440 nm with reference wavelength of 650 nm.
