Fig. 5. Typical (A) confocal and (B) STED microscopy images of Atto647N–Tf NPs inside HeLa cells. Insets are close-up views of the regions indicated with a dotted white square. Scale bar: 10 μm. (C) Statistical analysis of FWHM values obtained for >200 individual emitting species in both confocal (blue) and STED (red) microscopy images; the black curves represent corresponding Gaussian fits. (D) Schematic illustration of the internalization of multiple Tf NPs into one vesicle.
