Figure 2: The plasma-stimulated PBS is a stable and effective anti-cancer tool.

(a) The change of H₂O₂ concentration in the cold plasma-stimulated DMEM and PBS during the storage at 8 °C and 22 °C for 26 hours. (b) The change of H₂O₂ concentration in the cold plasma-stimulated PBS during the storage at 8 °C for 7 days. (c) The change of H₂O₂ concentration in the cold plasma-stimulated PBS during the storage at 8 °C and −25 °C for 3 days. (d) The change of anti-cancer capacity of the cold plasma-stimulated PBS during the storage at 8 °C and −25 °C for 3 days. (e) The effect of the cold plasma-stimulated PBS on the cell viability of U87MG, PA-TU-8988T, and MDA-MB-231 cells cultured in the cold plasma-stimulated PBS. (f) The change of H₂O₂ concentration in 37.3 μM H₂O₂-containing PBS during the storage at 8 °C for 3 days. The volume of solution for each well was 1 mL for all experiments. The treatment time for (a–d) was 1min and 2 min, respectively. Results are presented as the mean ± s.d. of three independently repeated experiments performed in triplicate (a–c,f) or in sextuplicate (d,e). For the cell viability, the data have been normalized to corresponding control group.Student’s t-test was performed and the significance is indicated as ***p < 0.005.