SummaryIncubation temperature and environmental pH were evaluated as independent and interdependent effectors of HSV in-activation. Kinetic studies at 4, 36, and 40° showed HSV inactivation was increased as the pH of the suspending medium was increased from 6.3 to 7.0 to 7.8. Conversely, the rate of HSV inactivation was antagonized and significantly reduced at each of these temperatures by adjusting the pH of the suspending culture medium to an acidic level. The utility of these observations as a means of enhancing the successful recovery of HSV from clinical specimens warrants consideration.This project was supported in part by research grants from the American Cancer Society (IN-113) and The National Institutes of Health (5 S07 RR05749-05). The technical assistance of Mr. Allen L. Richards is gratefully acknowledged.