Figure 3.
Analysis of the total intensity and width of the fluorescence profile. The total intensity I of Vamp-GFP from individual granules and the width squared, w2, of the radially averaged Gaussian fit of the intensity profile in each frame before, during, and after fusion were determined. Two events are shown. In fusion 148, the total intensity and the w2 increased simultaneously. In fusion 48, the total intensity rose before w2 increased significantly. The arrowhead along the x-axis indicates the frame immediately preceding fusion. The frame rate was 10 Hz.