US Patent 8992862 All-in-one means of separating blood components

A separation device including a first buoy, a second buoy, a first valve, and a second valve. The first buoy is mounted to a buoy guide post and slidably mounted within a separation chamber. The second buoy is slidably mounted to the guide post and movable between a first position and a second position. The second buoy closes the first valve and opens the second valve when in the first position. The second buoy opens the first valve and closes the second valve when in the second position. The second buoy has a density such that after spinning the device for a suitable period of time a first component of the composition is isolated between the first buoy and the second buoy and a second component of the composition is isolated between the second buoy and the end of the separation chamber that is opposite to a port.