Low-frequency ultrasound in vitro: Experimental system and ultrasound-induced changes of cell morphology

Ultrasound can temporary or permanently increase the membrane´s permeability for molecules that would otherwise be unable to enter the cell. Sonoporation that causes temporary changes on cell membrane can be used to introduce foreign material to the cell interior. Permanent increase of cell membrane permeability however causes cell death that can be used for water purification, waste water treatment, ballast water treatment in shipping, food processing and other purposes. To study these effects in an in vitro setting, we have built a custom low-frequency ultrasound experimental system based on an ultrasound transducer submerged in a waterbath. Using a hydrophone we have evaluated the ultrasound intensity in the waterbath with or without an ultrasound absorbing material lining the bath walls. In this system we evaluated effects of low frequency ultrasound on B16-F1 mouse melanoma cells.