Afterwards, medium was removed and 50 μL of CellEvent Caspase 3/7 green detection reagent along with Hoechst 33342 for nuclear staining (2 μM and 10 μM in PBS supplemented with 5% heatinactivated FBS) was added. Cells were incubated for 30 min at 37 °C in a humidified incubator before imaging by using the Thermo Fisher ArrayScan XTI high content screening (HCS) system (Thermo Scientific, Waltham, Massachusetts).