Oxidation and metabolic activity. (a) B16 melanoma cells were loaded with H2-DCF-DA and subjected to plasma treatment (120 s) or not. (b) Quantification of mean fluorescence intensities of the cells. (c) Mean fluorescence intensity of resorufin representative for cellular metabolic activity. Data are one representative (a, b) and mean + S.E. (c). Statistical analysis was carried out using t-test.