Transmission electron micrograph showing the extensive accumulation of darkly stained heterochromatin at the nuclear periphery typical of many differentiated cells. Heterochromatin is excluded from re...

Transmission electron micrographs of Opossum spermatogonia showing different regions within the nucleolus. One region is more lightly staining and fine textured, the other denser and more coarsely tex...

Transmission electron micrograph showing the highly compact nucleolus in the salamander hepatocyte. A finer textured central region is surrounded by a coarser region.

Transmission electron micrograph of Leydig cell nucleus from the domestic boar contains a region (arrow) thought to represent the single X chromosome which is largely heterochromatic. The chromosome i...

Transmission electron micrographs showing details of nuclear pores in thin sections of an erythroblast (above) and endothelial cell (below). Pores appear to be filled with dark staining material in th...

Electron micrograph of a thin section of fixed, embedded stained cells of Peranema trichophorum. Shown is a section of the "rodorgan', a bundle of 13-protofilment microtubules with pseudo-hexagonal sy...

Drosophila melanogaster thoracic tergotrochanter muscle from a four week-old wild-type animal. A longitudinal section of myocyte is displayed. Sections of parallel myofibrils are seen with distinguish...

Zymogen granule fraction Calf. Zymogen granules show their homogeneous content and limiting membrane. Image made available by James D. Jamieson and the Department of Cell Biology, Yale University S...

Zymogen granule fraction Calf. Section through a pellet of a zymogen granule fraction showing that the preparation mostly consists of morphologically unaltered zymogen granules. Image made available...

Transmission electron micrscope image of a thin section cut through an area of bone marrow area near the cartilage/bone interface in a mouse kneecap. Image shows small opening in the thin endotheliun ...