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Fig. 3. Immunoelectron microscopic visualisation of PcG proteins in (A) an
osmium-ammine-stained section of a paraformaldehyde-fixed SW480 cell
(anti-HPC2 labelling) and (B) in high pressure frozen and cryosubstituted rat
liver tissue (anti-BMI labelling); uranyl-lead stained. The primary antibodies
were revealed by goat anti-rabbit secondary antibody conjugated with 12 nm
colloidal gold particles. PcG proteins mainly occur at the periphery of
condensed chromatin (c). Some perichromatin fibrils are indicated by
arrowheads. Bars, 0.2 µm.