ACRYLIC TUBES ARE BETTER THAN POLYSTYRENE! Our 15mL centrifuge tube is produced from Acrylic which provides a stronger, chemically resistant and scratch resistant surface. Our tubes can be spun 2 ½ times faster in the centrifuge compared to polystyrene equivalents! The centrifuge tubes feature flat-top, plug-seal leak resistant screw caps, a large white writing area and printed graduation marks. Sterile tubes are RNase free, DNase free and Pyrogen free.  Acrylic (AC) Cap is made from High Density Polyethylene (HDPE) Dimensions: 17 x 120mm Sterile tubes are RNase/DNase and Pyrogen Free Spin Rate: 5000 RCF (6,160 x g) White graduation marks and large white writing area