FIG. 1.

Intranuclear distribution of RNA polymerase II molecules in noninfected HeLa cells using 7C2 monoclonal antibody. Glutaraldehyde fixation and Lowicryl K4M embedding. Uranyl acetate staining. In (a), gold particles are present in the interchroma-tin space excluding the cluster of interchromatin granules (IG) and its associated zone (star). The condensed chromatin masses (HC) also are devoid of labeling. The coiled body in (b) and the nucleolus (NU) in (c) are entirely devoid of labeling. C: cytoplasm. Bars represent 0.5 μm.