A multi-chambered pump-valve device for performing chemical processes, detections or analyses is described herein. The device includes a plurality of chambers having variable volumes in fluid communication with one another via one or more passageways. Liquid may be directed through the device by merely changing the volumes of two or more chambers. Despite the simplicity of the mode for transferring liquids in the device, complex chemical processing sequences may be performed using the device. A plurality of devices may be incorporated into a larger apparatus so that a plurality of chemical processing operations may be performed substantially simultaneously in parallel.