Transmission electron micrograph of a negatively stained preparation of ribosomes isolated from a 3-day old chick embryo that was maintained in a cold room for 24 hrs. The ribosome crystals seen in ...

Mouse 3T3 fibroblast shown in phase contrast (left) and immuno-stained for the nucleolar protein nucleostemin (right, green).

Mouse 3T3 fibroblast stained for the nucleolar protein nucleostemin (left, green) and 28S rRNA (right, red).

Mouse 3T3 fibroblast immunostained for the nucleolar protein nucleostemin (left, green) and fibrillarin (right, red) marking nucleolar fibrillar centers.

Rat NRK fibroblasts in phase contrast and stained for the nucleolar proteins nucleostemin (green) and fibrillarin (red). Panels at right show merge. Rows show different stages of mitosis, from top, ea...

Mouse 3T3 fibroblast immunostained for the nucleolar protein nucleostemin (left, green) and UBF (right, red) marking nucleolar fibrillar centers.

Thin section showing nucleolus of a Human neuroblastoma SK-N-SH cell imaged with a FEI Tecnai 20 energy filtered electron microscope at 200 KV and a 20 eV energy window. Overlay of net phosphorus dist...

Thin section showing nucleolus of a Human neuroblastoma SK-N-SH cell imaged with a FEI Tecnai 20 energy filtered electron microscope at 200 KV and a 20 eV energy window. Overlay of net phosphorus dist...

Mouse 3T3 fibroblasts stained for the nucleolar proteins nucleostemin (left panels, green) and fibrillarin (center, red). Top Row, control, center row 2h actinomycin D treatment, bottom row, 4h actino...

Thin section showing nucleolus of a Human neuroblastoma SK-N-SH cell imaged with a FEI Tecnai 20 energy filtered electron microscope at 200 KV and a 20 eV enegy window. Left panel shows 'phosphorus' i...