Figure 3. Endocytosis of 293T-Exo by R28 cells. (A) 293T-Exo uptake by R28 cells, as determined by the fluorescence assay. The nuclei were stained with DAPI (blue), the cytoskeleton was stained with tubulin (red), and 293T-Exo was stained with fluorescent-tag (green). Scale bar = 20 μm. (B) Efficacy of endocytosis of 293T-Exo by R28 cells displayed a dose-dependent pattern and saturable (more than 16 μl of 293T-Exo). (C) Efficacy of endocytosis of 293T-Exo by R28 cells displayed a temperature-dependent pattern. Data are presented as mean ± SD. **P < 0.01, ***P < 0.001.