Fig. 3. Immunofluorescence confocal microscopy and cryothin-section immunogold label electron microscopy of adipophilin in lipid droplets of AcLDL-treated macrophages. (A) BODIPY staining for neutral lipids. (B) Immunofluorescence labeling of adipophilin. (C) Merged image of A and B. High magnification views (inset in C) show a rim of adipophilin labeling around the neutral lipid core of the droplet. Immunogold labeling (18 nm gold) for adipophilin in cryothin sections examined by electron microscopy reveals prominent labeling at the surface of the lipid droplet (LD), consistent with the immunofluorescence results. Bars, 5 µm (A-C); 0.2 µm (D).