Double-Strand Breaks in Genome-Sized DNA Caused by Ultrasound.
DNA double-strand breaks (DSBs) caused by ultrasound were evaluated in a quantitative manner by single-molecule fluorescence microscopy. We compared the effect of time-interval (or pulse) sonication to that of continuous wave (CW) sonication at a fixed frequency of 30 kHz. Pulses caused fewer DSBs than CW sonication under the same total input ultrasound energy when the pulse repetition period was above the order of a second. In contrast, pulses caused more DSBs than CW sonication for pulse widths shorter than a second. These effect of ultrasound on DNA were interpreted in terms of the time-dependent decay in the probability of breakage during the duration of a pulse. We propose a simple phenomenological model by considering a characteristic decay in the probability of DSBs during single-pulse sonication, which reproduces the essence of the experimental trend. In addition, a data analysis revealed a characteristic scaling behavior between the number of pulses and the number of DSBs.
Faculty of Life and Medical Sciences, Doshisha University, Tatara-Miyakodani, Kyotanabe, Kyoto, 610-0321, Japan.
Rinko
R
Kubota
Faculty of Life and Medical Sciences, Doshisha University, Tatara-Miyakodani, Kyotanabe, Kyoto, 610-0321, Japan.
Yusuke
Y
Yamashita
Faculty of Life and Medical Sciences, Doshisha University, Tatara-Miyakodani, Kyotanabe, Kyoto, 610-0321, Japan.
Takahiro
T
Kenmotsu
Faculty of Life and Medical Sciences, Doshisha University, Tatara-Miyakodani, Kyotanabe, Kyoto, 610-0321, Japan.
Yuko
Y
Yoshikawa
Center for Frontier Medical Engineering, Chiba University, Chiba, 263-0022, Japan.
Kenji
K
Yoshida
Faculty of Life and Medical Sciences, Doshisha University, Tatara-Miyakodani, Kyotanabe, Kyoto, 610-0321, Japan.
Yoshiaki
Y
Watanabe
Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, 525-8577, Japan.
Tadayuki
T
Imanaka
Faculty of Life and Medical Sciences, Doshisha University, Tatara-Miyakodani, Kyotanabe, Kyoto, 610-0321, Japan.
Kenichi
K
Yoshikawa
D004247:DNA / Q000737:chemistry* / Q000235:genetics; D053903:DNA Breaks, Double-Stranded; D008856:Microscopy, Fluorescence; D000069453:Ultrasonic Waves
D004247:DNA
double-strand breaks; fluorescence microscopy; genomic DNA; single-molecule studies; ultrasound