Keratinocytes were incubated in media containing 50 nM sytox orange (ThermoFischer #S11368) and 0.2 µg/mL Hoechst 34342 (Sigma #H3570). Cells were stimulated and imaged over time using the Biotek Cytation 5 Cell Imaging Multi-Mode Reader with fluorescent DAPI and RFP filter cubes at 37 °C with 5% CO2. Cellular analysis was performed with built-in Gen5 Cytation 5 software and DAPI/RFP double-positive cells were quantified with built-in software.