Ultrasonic cell lysis in vitro upon fractional, discontinuous exposure vessel rotation

In polystyrene exposure vessels, a substantial fraction of suspended P388 cells was lysed by exposure to cw, 1-MHz ultrasound (5 W cm-2 spatial peak intensity, 5 min) in stationary vessels or those subjected to a small number of half rotations. Lysis was increased significantly by two half-rotations during exposure relative to stationary vessels. Lysis in stationary exposure vessels is generally considered to be minimal; it is shown that approximately 40% cell lysis occurs in 15%-20% of the stationary tubes. This result appears to relate to the distribution of random defects on the exposure vessel walls.