A Cytochemical Study of Basic Proteins in Adenovirus-infected Cells

On staining adenovirus-infected cells with phenanthrenequinone and with copper phthalocyanin-neutral red, characteristic structures in the form of rings and rosettes were observed. These structures could also be visualized by phase-contrast microscopy and by fluorescent antibody staining with adenovirus P antiserum. The cytochemical staining could be blocked by pre-treatment of the fixed cells with benzil, and the result suggested that the rings and rosettes were the sites of accumulation of arginine-rich basic proteins.