Genomic DNA was extracted after plasma exposure and media in a 48 well plate (1 ml per well) was exposed to D2O + N2 plasma for 0 (control), 3 min and 0.5 µM of actinomycin D for OH-dG detection, 1 % agrose gel and CD analysis. Treated cells were subjected to genomic DNA extraction kit. Genomic DNA was extracted following a standard molecular biology protocol and re-suspended in 50 µl water24 (link). The same amount of genomic DNA (2 mg) extracted from cells was used for the detection of 8-OH-dG level using a oxidative DNA damage ELISA kit (Cell Biolabs, inc. USA), same amount of DNA was loaded on a 1 % agarose gel and runned for 1 h. Then, the DNA bands were photographed, after staining with ethidium bromide.