Systems and methods for isolating and characterizing various target materials of a suspension are disclosed. A suspension suspected of containing the target materials is added to a tube. A float with a specific gravity corresponding to that of the target material is inserted into the tube. The tube, float, and suspension are centrifuged together causing the various materials suspended in the suspension to separate into different layers along the axial length of the tube according to their specific gravities. The float and/or tube are configured to drive the various target materials to a region of space between the float and inner wall of the tube.