0.5% Tween-20) for 18-20 h. After washing with 0.1M PBS, the sections were exposed to biotinylated secondary IgG for 1 h (1:200; Vector Laboratories). After secondary antibody incubation, slides were incubated in ABC for 1 h (Vector Laboratories), and staining was visualized with 3,3-diaminobenzidine (DAB; Pierce Laboratories). Sections were counterstained with Fast Red (Vector Laboratories). Omission or dilution of the primary antibody resulted in lack of specific staining, thus serving as a negative control for antibody experiments.
