Fig. 4. (a) Schematic illustration of cell entry properties of constructs including SNA and four different sized X-SNAs. (b) Cell internalization properties of native LOX, SNA, and four different sized X-SNAs determined by flow cytometry. (c) Correlation curve showing the cellular uptake index of different sized constructs. (d) Flow cytometry analysis of HeLa cells incubated with 80 nm X-SNA under different inhibitor treatments. (e) Confocal images (left) and fluorescence intensity profiles (right) showing colocalization of X-SNA probes with early endosome and lysosome in HeLa cells. Error bars indicate standard deviations of three independent measurements.