Cellular inactivation by heat and shear.

Inactivation of Chinese hamster V79 cells in vitro by a temperature elevation to 43 degrees C and with Couette shear flow was investigated. The shear stresses were chosen to mimic those produced by ultrasound of approximately 3 MHz and 3 W/cm2 within the chambers employed by earlier investigators studying ultrasonic inactivation of cellular processes. The combined shear and thermal stresses produced survival curves exhibiting a summating effect among these two stresses and remarkably similar to the ultrasound/thermal survival curves.