Fig. 4. Typical confocal fluorescence images of HeLa cells after incubation with ((A), red) 1 nM Atto647N–Tf NPs, and ((B), green) stained with Rab5a–GFP fusion protein-based early endosome marker. (C) Yellow spots in the overlap image represent Atto647N–Tf NP colocalization with endosomes. Scale bar, 20 μm. (D) Quantitative comparison of Atto647N–Tf NP internalization by HeLa cells in the presence and absence of chlorpromazine or free Tf in the cell culture medium. Results are averages >60 cells; error bars denote standard errors of the mean.
