Fig. 6. Effect of BFA on Syt IX, internalized Tfn and mannosidase localization. RBL-Syt IX⁺ cells were either untreated (A,C) or treated for 30 minutes at 37°C with BFA (5 µg/ml) (B,D), or allowed to internalize FITC-conjugated Tfn (50 µg/ml) for 1 hour (E,F) without (E) or with BFA (5 µg/ml) added for the last 30 minutes of Tfn internalization (F). Cells were subsequently labeled with either anti-C2A-Syt IX (A,B) or with anti-mannosidase II (C,D), followed by rhodamine-conjugated donkey anti-rabbit antibodies. Bars, 3 µm (A,B); 5 µm (C-F).