Fig. 1.

Schematic diagram of experimental setup. The zirconate titanate piezoelectric transducer, bonded on a plastic platform, was connected to an impedance matching transformer which was serially connected with an amplifier and a computer-driven function generator. After filled with culture medium containing cells and/or PEI/DNA complexes, the tubular acoustic chamber was placed on the PZT transducer smeared with glycerol as the coupling agent. The acoustic waves, transmitted from the transducer at 1 MHz and 25 V_p-p, were reflected from the glass coverslip capped on the top of the chamber. The interference of transmitted and reflected waves led to the formation of ultrasound standing wave fields.