Abstract
Adenovirus Type 2 was grown on HeLa cells and purified by CsCl-gradient centrifugation. Three regions of bands were obtained, differing by their sedimentation rate and density in CsCl solutions. Electron microscopic investigations of negatively stained preparations show icosahedral particles with 252 subunits for the main virus region. The lighter bands consist of empty shells. A plaque test suiting the conditions was developed.