Figure 4. SEM analysis of dendritic cells and macrophages in radicular granulomas. (A) Secondary electron image showing an HLA-DR+ oval cell without cytoplasmic processes (macrophage). Bar = 5 µm. (B) Backscattered electron image of the same cell in (A). Bar = 5 µm. (C) Secondary electron image showing an HLA-DR+ slender cell with long cytoplasmic processes (dendritic cell). Bar = 5 µm. (D) Back-scattered electron image of the same cell in (C). This cell contains more gold particles as compared with the cell shown in (B). Bar = 5 µm. (E) Density of colloidal gold particles on HLA-DR+ dendritic cells and macrophages per unit area (150 nm x 100 nm). Results are expressed as mean ± SD (n = 14). **p < 0.01.