Fluid control and processing method

Embodiments of the invention facilitate processing of a fluid sample according to different protocols using the same apparatus, for instance, to determine the presence or absence of an analyte in thesample. In a specific embodiment, a fluid control and processing system for controlling fluid flow among a plurality of chambers comprises a body including a fluid sample processing region continuously coupled fluidicly with a fluid displacement chamber (50). The fluid displacement chamber isdepressurizable to draw fluid into the fluid displacement chamber and pressurizable to expel fluid from the fluid displacement chamber. The body includes a plurality of external ports (42, 46). The fluid sample processing region is fluidicly coupled with at least two of the external ports. The fluid displacement chamber is fluidicly coupled with at least one of the external ports. The body is adjustable with respect to the plurality of chambers to place at least one of the external ports selectively in fluidic communication with the plurality of chambers.