Fig. 7. (A) Tfn-positive endosomes co-stain with Rab 11. RBL-Syt II^- cells were treated at 37°C with TPA for 2 hours and incubated with FITC-Tfn (50 µg/ml) for the last 5 minutes of incubation. The cells were subsequently processed for immunofluorescent staining using rabbit polyclonal anti Rab 11 antibodies followed by Rhodamine-conjugated donkey anti-rabbit antibodies. A-Tfn (green), B-Rab 11 (red), C-Merge. Data represent one of two separate experiments. (B) PKC-positive vesicles co-stain with serotonin. RBL (A-C) and RBL-Syt II^- (D-F) cells were treated at 37°C with TPA for 4 hours. The cells were subsequently processed for immunofluorescent staining using rabbit polyclonal anti-PKC and mouse monoclonal anti-serotonin antibodies followed by Rhodamine-conjugated donkey anti-rabbit antibodies and FITC-conjugated donkey anti-mouse antibodies. A, D-PKC (red), B, E-serotonin (green), C, F-Merge. Data represent one of three separate experiments.