The CellASIC flow control systems use pneumatic pressure to direct microfluidic flows. This allows for a "flow switching" type of experiment not easily possible with alternate perfusion systems. For example, this system lets one culture cells on the microscope stage, expose the cells to one solution for a specified period of time, switch to a completely different solution and image the response, switch solutions again, etc. The current ONIX system is equipped with 8 independent flow lines, enabling a wide range of applications. In addition, the programmable software interface makes setting up time-varying exposures easier than ever.