Fisherbrand 2.0mL MCT Graduated microcentrifuge tube with flat top cap violet Produced from clarified homopolymer polypropylene, the tubes stand up to temperatures ranging from -90 to +121C and are certified RNase- and DNase-free. The cap has a smooth, rounded flange and positive seal design. A frosted writing surface on the side of each tube provides for easy identification. Choose No Stick