Manufactured from polypropylene. These 1.7 ml pre-lubricated microcentrifuge tubes have a low adhesion surface, which provides optimum sample yields for biotechnology applications. The cap design allows repeated openings and closings, while resisting popping from internal pressure. Membrane in cap middle is thin enough for syringe penetration. Writing surfaces on cap and side wall provide easy sample identification. Temperature range: -180°C to +121°C. Maximum RCF: 30,000 g. Certified RNase-, DNase-free. Graduated.