Abstract
This virus degrades upon heating at 61[degree] or 85[degree]C into infectious ribonucleic acid (RNA) provided that environmental ribonuclease (RNase) is either inactivated by hot sodium dodecylsulfate or is completely removed prior to heating. Heat alone is sufficient to produce infectious RNA, and hot detergent only serves to inactivate RNase. Phenol treatment of heat-derived infectious RNA did not increase the amount of infectious RNA present. An earlier hypothesis is negated that boiling at 100[degree]C in 0.1% SDS only inactivates an infection-initiating property of the virus protein, leaving a phenol-extractable infectious core. The newer interpretation is that thermally-released RNA is not completely inactivated during 5 minutes boiling in detergent.