Boil-proof cap
Withstand 28,000 x g
Easy to open, easy to close
Double, high pressure locking ring
RNase, DNase and pyrogen free
Unsurpassed clarity
Frosted writing surface and graduations
Ultra smooth interior-low liquid retention
Made from highest quality, virgin, single melt polypropylene
Our latest Posi-Click design incorporates over 20 improvements that have made these tubes our #1 seller. Tubes seal easily with a distinct "click" and stay closed through incubation, freezing and boiling procedures. The unique closure system provides a tight seal that is actually strengthened by internal pressure. It will withstand boiling for 5 to 10 minutes. These tubes represent our fourth generations of improvements, incorporating over a dozen advanced features. Shouldn't you be using the best