Figure 2. Cellular uptake of DOX, M-DOX and Tf-M-DOX/PSO in K562/DOX cells. (A) Cells were treated with DOX, M-DOX and Tf-M-DOX/PSO and then photographed by fluorescence microscopy. All samples were treated for 0.5 h or 1 h at 37°C. (B) Calculations of various micelle uptake by flow cytometry. Untreated cells were used as a negative control. (C) Positive percent of cells with fluorescence were illustrated. (D) Mean intensity of fluorescence in cells after 30 min or 60 min [of what?] (n=3/group). ** indicates P < 0.05.