Our medium exchange protocol expands the functionality of our acoustofluidic device from bacteria trapping to medium exchange. The protocol consists of three steps, namely: capture, wash, and release. In the first step, we filled the channel with cell solution at a flow rate of 10 µL min -1 and activated the acoustic trapping of the cells through wall vibration. After two minutes, we stopped the flow of cell solution and flushed the channel with ultrapure water at a flow rate of 10 µL min -1 for 30 seconds to wash the cells and remove remaining cell suspension liquid. Finally, we turned off the acoustic excitation and increased the flow rate of ultrapure water to 20 µL min -1 for 60 seconds, which, given lack of acoustic forces during this step, allowed to remove the cells from the chamber while being suspended in the new medium. The medium exchange protocol's execution is computer controlled by a custom-written Python script to synchronize the acoustics and regulation of flows.