An improved biological fluid filtration system is shown having, seriatim, a blood container, a biological fluid filtration device downstream of the blood container, and a blood receiving container downstream of the biological fluid filtration device; a bypass line is provided to allow fluid communication between the blood container and the blood receiving container, the bypass line includes a loop, the loop of the bypass line being configured to be disposed above the blood container at a sufficient height to prevent the passage of fluid around the leukocyte depletion device; the loop of the bypass line being disposed in a tube support device, the tube support device being configured to support substantially the entire weight of the biological fluid filtration system without substantially crimping said bypass line.