Fig. 4. Localization of the a3 isoform in pancreatic ß-cells. (A) The localization of a3 is shown by electron-dense silver-enhanced immunogold particles (arrows indicate examples): mt, mitochondria; SG, secretory granules. Bar, 1 µm. (B) Quantification of gold particle frequency in secretory granule (SG) or other compartments. Approximately 80% of total gold particles (450 µm2 x 6 sections, n=1193) were distributed in the dense-core granules. MVB, multi-vesicular body; mt, mitochondria.