PI fluorescence (DNA content) histograms of Caco-2 cells after exposure to ZnO NPs. (A) Control culture (non-exposed). (B) Cells exposed to 26-nm ZnO NPs at 12.5 μg/ml. (C) Cells exposed to 26-nm ZnO NPs at 50 μg/ml. The data are presented as the mean ± SD of three independent experiments.
Kang et al. Nanoscale Research Letters 2013 8:496 doi:10.1186/1556-276X-8-496