Fig. 6

Evaluation of ROS production on three-day old spheroids after exposure to different doses of [⁶⁴Cu]CuCl₂, probed with H₂DCFDA. A–D ROS production by U87, U373, T98G, and RA spheroids, respectively, using the H₂DCFDA method based on the detection of DCF fluorescence. Results are presented as the fold change to each cell line's respective untreated control at 1 h as a function of the time of exposure. Data are presented as mean values ± S.E.M. of 2–3 independent assays. *p < 0.05