Fig. 5. Dynamics of EGFP-Rab3A on newly synthesised and old secretory granules in PC12 cells. PC12 cells were transfected to express the indicated EGFP-tagged protein and examined 18, 30 or 54 hours post transfection. Regions of interest (ROIs) in each cell were bleached with high intensity laser and the fluorescence recovery of these areas was followed over time. Fluorescence in the ROI was recorded over time during low-intensity imaging. The data are shown as mean ± s.e.m. for 32 EGFP-Rab3A expressing cells at 18 hours, 10 at 30 hours and 27 at 54 hours. The data were corrected for general photobleaching for each cell at each time point and normalised by setting the initial fluorescence value for each cell to 100 and with the initial post-bleach data point set to 0.