Figure 4.

Detection of formation of reactive oxygen species by flow cytometry. To check whether SPION^Citrate leads to the formation of ROS, the EL4 cells were stained with DCFH-DA. When ROS is generated, DCFH is oxidized to DCF, which has a strong fluorescent effect. In the beginning, after 6 hrs, 24 hrs and after 48 hrs of incubation with SPION^Citrate, cells were additionally stained with DiI and PI for detection of viable cells. The results were displayed as relative cell count (A) and as percentage of cell count (B). The experiment was performed in triplicate in at least two independent experiments. The mean values with standard deviations are shown. Significance of stressed cells compared to hydrogen peroxide 1 mM is represented by asterisks.

Abbreviations: DCF, dichlorofluorescein; DCFH, dichlorofluorescin; DCFH-DA, 2′,7′-dichlorofluorescin diacetate; DiI, DiIC₁(5) (1,1′-dimethyl-3,3,3′,3′-tetramethylindodicarbocyanine iodide); PI, propidium iodide; ROS, reactive oxygen species; SPION, superparamagnetic iron oxide nanoparticle.