Fig. 4. Cy3mBSA is internalized into GFP-Rab5-positive early endosomes distinct from LR-Dex early endosomes that are devoid of GFP-Rab5. Hemocytes from Collagen-Gal4;UAS-GFPdRab5 larvae were incubated for 45 seconds with Cy3mBSA (A-C) or LR-Dex (D-F) prior to fixation, permeabilization and imaging on wide-field microscope. At 45 seconds, a fraction of Cy3mBSA-labeled structures (A, red in C; small arrows) are also positive for GFP-dRab5 (B, green in C; small arrows). Several peripherally distributed Cy3mBSA-labeled structures (A, red in C; small arrowheads) are negative for GFP-dRab5 (B, green in C) and are likely to be surface accessible (see Fig. 3). LR-Dex-containing endosomes (D, red in F; arrowheads) do not colocalize with GFP-dRab5-positive structures (E; green in F; small arrows). Insets show magnified view of the area marked by an asterisk. Bar, 5 µm; inset, 1 µm.