ULTRASONIC DEGRADATION OF BIOLOGICAL MACROMOLECULES UNDER CONDITIONS OF STABLE CAVITATION .2. DEGRADATION OF DEOXYRIBONUCLEIC ACID

Solutions of T7 bacteriophage or calf thymus DNA arc degraded in solution by ultrasonic fields of low intensity in the presence of vibrating air bubbles but are not degraded at these low intensities when such bubbles are absent. Evidence is presented for the hydrodynamic nature of the observed degradation and theoretical simulation of a plausible degradation mechanism is compared with experimental degradation studies. It is concluded that degradation of such linear macromolecules as DNA may occur as a result of stresses induced in the macromolecule; these stresses are the result of a relative movement of solvent molecules and the macromolecules in the time‐independent flow of solvent near the vibrating bubbles. Copyright © 1968 John Wiley & Sons, Inc.