Fig. 10. Adipophilin immunogold labeling (12 nm gold) in side-by-side convex and concave fractures of ER cups. The example at the top left of the field (magnified at top right) has been concavely fractured, showing the E-face of the ER membrane adjacent to the lipid droplet and the P-face of its partner membrane. The example at the bottom right (magnified at bottom left) has been convexly fractured to reveal the P-face of the membrane closest to the lipid droplet and the E-face of its partner membrane. No labeling is observed on either E-face view. The P-face of the ER membrane closest to the lipid droplet (lower example) is more heavily labeled than that of the partner membrane (upper example). Bar, 0.5 µm.