Various morphologies of Caco-2 cells stained with AO/EB. VN would have a uniform bright green nucleus and orange cytoplasm. VA, whose membranes are still intact but has started to cleave its DNA, would still have a green nucleus, but NVA, whose chromatin condensation becomes visible in the form of bright orange areas of condensed chromatin in the nucleus (EB predominates over AO), and NVN will have a uniform bright orange nucleus. (A) The control group, (B) 26-nm ZnO NPs at 50 μg/ml, (C) 26-nm ZnO NPs at 12.5 μg/ml, (D) 62-nm ZnO NPs at 50 μg/ml, (E) 62-nm ZnO NPs at 12.5 μg/ml, (F) 90-nm ZnO NPs at 50 μg/ml, and (H) 90-nm ZnO NPs at 12.5 μg/ml. VN, viable cell; VA, early apoptotic cell; NVA, late apoptotic cells; NVN, necrotic cell; EB, ethidium bromide; AO, acridine orange.
Kang et al. Nanoscale Research Letters 2013 8:496 doi:10.1186/1556-276X-8-496