Herpesvirus saimiri. III. Plaque Formation Under Multi Agar, Methyl Cellulose and Starch Overlays 1

Summary Herpesvirus saimiri produced plaques in cultures of fetal squirrel monkey heart, lung, intestine, and kidney and in owl monkey kidney and marmoset kidney cell cultures. The plaque populations in all cell types were heterogeneous in respect to size. Harvests of single plaques produced heterogeneous plaque populations on serial plating. Plaques were most numerous under methyl cellulose. Under agar, plaques were less numerous but were larger. Protamine sulfate and, to a limited degree, DEAE-dextran stimulated plaque production under agar while arginine had no effect. Plaques also formed under starch but were difficult to visualize. The number of plaques was directly proportional to the virus dilution, was also proportional to the volume of the inoculum, and was reduced by specific antiserum.