Ultrasonic scission of deoxyribonucleic acid in aqueous solution i. conditions for sonication and molecular weights of sonicated samples

Abstract

By irradiating ultrasonic wave (20 kHz).to calf thymus deoxyribonucleic acid (DNA) in aqueous solution (2 mg ml−1 containing 0.2 M NaCl) at 0°C, the molecular weight (Mw) was degraded from 8×106 to ca. 2×105 without any noticeable denaturation. The dependence of the molecular weight of sonicated DNA on the irradiation intensity was examined by varying ultrasonic energy levels. The molecular weights were remarkably decreased with the increase in ultrasonic power from 25 to 105 W, and reached a steady value (Mw=2.4×105) at 100—200 W. © 1986 The Society of Polymer Science, Japan.