A device and method are provided for facilitating extraction of a fraction from a biological sample. The biological sample includes non-desired material and a fraction-bound solid phase substrate. The device includes an input zone for receiving the biological sample therein and a phase-gate zone for receiving an isolation buffer therein. An output zone receives a reagent therein. A force is movable between a first position adjacent the input zone and a second position adjacent the output zone. The force urges the fraction-bound solid phase substrate from the input zone, through the phase-gate zone and into the output zone.