Ribonuclease activities associated with purified foot and mouth disease virus.

Ribonuclease activities internally and externally associated with purified foot-and mouth disease virus were detected. The outer activity was easily removed by cesium chloride or by detergent (Sarkosyl). The inner activity is not removable by any procedure used and could be the enzyme responsible for the heterogeneity normally observed in the extracted FMDV-RNA. It is not known at present if both activities are related to the same or to different enzymes.