Gas plasma and radiotherapy introduced reactive oxygen and nitrogen species (ROS) in B16F10 melanoma cells. (A–C) B16F10 cells were exposed either to gas plasma (15 s) or radiotherapy (8 Gy), and intracellular ROS were measured immediately (A) and 24 h (B) after exposure by flow cytometry, and quantified (C); (D,E) mitochondrial mass was determined by flow cytometry (D) and quantified (E) at 24 h post-exposure. Data are representative and mean +SE of three experiments. Statistical analysis was performed by one-way ANOVA. Utr = untreated, PL = plasma, Rad = radiotherapy, MFI = mean fluorescent intensity; *** = p < 0.001.