Electron microscopy of cells infected with adenovirus type 2.

An electron microscope study of two strains of human adenovirus type 2 revealed the production of intranuclear paracrystalline formations by one of the strains. The crystals were composed of cylindrical tubules 25.0 nm in diameter arranged in a crystalline lattice with a periodicity of 75.0 nm. They appeared at 36 hr postinfection in nuclei which contained viral particles. Prolonged treatment with proteolytic enzyme only partially digested the crystals. The relationship of these crystals to similar nonviral crystals found in association with other virus infected-cells was discussed.