Abstract: Integral chromatography unit having an inlet and an outlet, and comprising one or more membranes interposable in the internal volume of the unit between the inlet and outlet. In certain embodiments, each of the membranes is allotted adequate space within the unit to swell by the placement of one or more spacers. Fluid entering the unit through a fluid inlet passes the membrane(s) and spacer(s) prior to exiting the unit through a fluid outlet.