Electron microscopic localization of 1D9- and anti-Arf6-immunoreactive proteins in Nycodenz-purified peroxisomal fractions immobilized on poly-L-lysine-coated grids. (A) Prestained organellar fraction (see Methods). Rabbit anti-PMP70 (α-PMP70) and mouse monoclonal 1D9 were used as primary antibodies, and 12 nm gold-conjugated anti-rabbit IgG (α-12 nm gold) and 18 nm gold-conjugated anti-mouse IgG (α-18 nm gold) as labels. (B) Poststained organellar fraction (see Methods). Rabbit anti-PMP70 (α-PMP70) and mouse anti-Arf6 (α-Arf6) were used as primary antibodies, and the same secondary antibodies were used as in panel A. Negative controls were included in parallel in which the primary antibodies were omitted (left panels). The original magnification was 60,000-fold (upper panels), 27,800-fold (lower left panel), or 46,460 fold (lower right panel); the scale bar represents 500 nm.