To determine possible adverse effects of DiD on cell function, PCa cells (PC3, DU145, C42B) were stained with DiD (0.5 μM and 2 μM), and a selection of functional assays were performed. (A) Cell proliferation was measured by MTS assay. (B) Cell migration was assessed using a wound-healing assay. Original magnification, 10x / 0.25 Ph1 ADL. Scale bars: 250 μm. After 2 days of DiD staining, (C) apoptosis was analyzed by flow cytometry with Annexin V staining and (D) the number of dead cells was counted by trypan blue staining. Data are presented as mean ± standard deviation from triplicate determinations.