Large white printed writing spot, extra-clear printed black graduations and earth-friendly packing. Certified free of Nuclease, Endotoxins and Metals.  PCI brand centrifuge tubes offer excellent quality at an affordable price.  They are available in two sizes: 15 and 50 ml.  Both sizes are made from a special polypropylene resin that is clearer than other polypropylene tubes but stronger to permit centrifuging to 12,000 RCF for the 50 ml size and 7,500 RCF for the 15 ml size. All tubes have flat caps that are easy to label and will fit standard rotors.  Tubes are autoclavable (122°C) and freezable (-90°C) and are non-cytotoxic. Polyethylene caps and cap liners are not autoclavable. Dimensions: 15 ml size, 17mm OD (15 mm ID) x 118mm L; 50 ml size, 29 mm OD (27 mm ID), 115 mm L.