Electron microscope observations of liver cells inoculated with lipovirus

The process of infection of liver cells with lipovirus apparently ends in the production of bodies appearing to be aggregates of hollow spheres. In thin sections these spheres appear like rings of very dense material. Nine days after infection, the nucleoplasm of cells contained individual rings about 15 mμ in diameter with a 10 mμ hole, as well as small clusters of rings. Large aggregates up to 100 mμ in diameter, were found in the cytoplasm and just outside the cell membrane. The location of the rings and of their aggregates of various sizes suggests that the elements arise in the nucleoplasm, form into clusters, and move through the cytoplasm to the exterior of the cell. Pellets of cell-free material, known to be infective, were found to contain aggregates of ring elements similar in appearance to those found in the whole cells.