The extraordinary strength, safety and reliability of our Screw-Cap tube lets you perform procedures that simply can’t be done with other tubes. Spin it, store it, transport it (even by air). Boil it, irradiate it, immerse it in the vapor phase of liquid nitrogen-it’ll stand up to the test! Inside the screw cap, our ethylene propylene O-Ring formsa secure and leakproof seal. Our screw cap’s square threads won’t strip-and they’re on the outside of the tube, so you minimize the risk of contaminating your sample-or letting it contaminate you.Our Screw-Cap tube is ideal for any sample-processing or storage application imaginable-and especially for working with valuable or hazardous cells and materials.