Trust your precious samples with our most durable and versatile screw cap microcentrifuge tubes developed for sercure use in a variety of laboratory environments. Tubes feature and easy 3/4 turn thread for one handed operation and compatible leak-proof o-ring screw cap. Olympus brand screw cap microtubes are ideal for general purposes, boiling applications, short or long-term cryogenic storage (-20oC, -80oC or LN2vapor phase), etc. Rated to > 20,000 x g. Certified RNase, DNase & DNA free. Sterile, preassembled versions are also certified free of pyrogens.