The level of Hydrogen Peroxide in HeLa Cells in an Ozonated Medium.

We studied the role of hydrogen peroxide in the response of tumor cells to treatment with ozonated culture medium. Changes of the level of hydrogen peroxide in tumor cells incubated in ozonated medium were detected by using fluorescence microscopy and genetically-encoded sensor HyPer2. Modifications of fluorescent properties of the sensor reflecting accumulation of hydrogen peroxide in the cell cytoplasm were detected within 70 min from the start of exposure. The concentration of hydrogen peroxide continued to increase until 375 min. The revealed changes support the involvement of hydrogen peroxide in the cell response to ozone treatment.