FIG. 2.

Intranuclear distribution of RNA polymerase II molecules in HeLa cells following the use of mAb H5. Formaldehyde fixation, Lowicryl embedding, and uranyl acetate staining. Bars represent 0.5 μm. (a, b) Gold particles are numerous over a cluster of interchromatin granules (IG) in (a) and over a small cluster of RNP fibrils (arrow) in (b). They are scattered over the surrounding nucleoplasm, (c, d) The coiled body (CB) in (c) and the interchromatin granule-associated zone (star) in (d) are devoid of gold particles. C: cytoplasm; IG: cluster of interchromatin granules.