A fluid control and processing system for controlling fluid flow of a fluid sample among a plurality of chambers, the system comprising: a housing containing the plurality of chambers; a valve body including a single main fluid processing region continuously coupled fluidicly with a single fluid displacement region, the fluid displacement region being depressurizable to draw fluid into the fluid displacement region and pressurizable to expel fluid from the fluid displacement region, the valve body including a plurality of external ports (42,46), the main fluid processing region being fluidicly coupled with at least one external port, the fluid displacement region being fluidicly coupled with at least one external port (42,46) of the valve body, and the valve body being rotatably adjustable relative to the plurality of chambers to place at least one external port selectively in fluidic communication with the plurality of chambers, wherein the valve body has a disk portion and a tubular portion, with the single main fluid processing region contained within the disk portion and the fluid displacement region contained within the tubular portion wherein the disk portion has a planar external port surface, wherein at least one of the plurality of chambers is a processing chamber, the processing chamber including a first port and a second port for selectively communicating with at least one of the external ports (42,46) of the valve body, the processing chamber providing an additional fluid processing region, the processing chamber containing a fluid processing material, which is an enrichment material that captures a target from the fluid sample or a depletion material that traps unwanted material from the fluid sample. a housing containing the plurality of chambers; a valve body including a single main fluid processing region continuously coupled fluidicly with a single fluid displacement region, the fluid displacement region being depressurizable to draw fluid into the fluid displacement region and pressurizable to expel fluid from the fluid displacement region, the valve body including a plurality of external ports (42,46), the main fluid processing region being fluidicly coupled with at least one external port, the fluid displacement region being fluidicly coupled with at least one external port (42,46) of the valve body, and the valve body being rotatably adjustable relative to the plurality of chambers to place at least one external port selectively in fluidic communication with the plurality of chambers, wherein the valve body has a disk portion and a tubular portion, with the single main fluid processing region contained within the disk portion and the fluid displacement region contained within the tubular portion wherein the disk portion has a planar external port surface, wherein at least one of the plurality of chambers is a processing chamber, the processing chamber including a first port and a second port for selectively communicating with at least one of the external ports (42,46) of the valve body, the processing chamber providing an additional fluid processing region, the processing chamber containing a fluid processing material, which is an enrichment material that captures a target from the fluid sample or a depletion material that traps unwanted material from the fluid sample.