Amber polypropylene tubes significantly reduce light penetration through the tubes. They are ideal for the storage of light sensitive materials or for applications involving light sensitive reactions. These 15 ml conical centrifuge tubes are graduated and have large labeling areas. In supported rotors, the 15 ml tubes are rated up to 15,000 x g. In non-supported rotors, they are rated up to 3500 x g. Sterile.