A fluidic device for a cartridge for testing biological samples is disclosed herein. In an embodiment, the fluidic device includes a fluidic chamber, at least one microfluidic channel in fluid communication with the fluidic chamber, a venting port configured to apply a pneumatic force to the fluidic chamber, at least one passive valve located within the at least one microfluidic channel and configured to allow or stop fluid flow through the at least one microfluidic channel based on a pressure difference, and a controller configured to control the pneumatic force applied to the fluidic chamber via the venting port.