Our tubes feature an improved easy open snap seal. Tubes with ultimate boiling protection or for basic boiling applications are available. An ergonomically designed positive seal cap makes these tubes easier to open and close than other tubes. All tubes feature frosted writing surfaces on the cap and side for smear resistant labeling. Graduations every 100µl enable easier estimation of tube contents and more reliable rotor balancing.Molded from clarified virgin polypropylene for unmatched strength and clarity. Certified free from RNase, DNase, DNA & PCR inhibitors. Also Endotoxin-Free.