SureSeal™ sterile screw-cap microtubes come in a variety of sizes, cap configurations, graduation options, and now light-blocking amber. Made from ultra-clear polypropylene, these screw cap microtubes include assembled caps with silicone O-rings that assure a leakproof seal from -90°C to +121°C. All SureSeal™ screw cap microtubes are sterile, RNase, DNase, & pyrogen free and may be centrifuged at up to 22,000xg. • Ultra-clear polypropylene • Molded or non-graduated options • Leak-proof O-ring seal • Light-blocking amber available • Sterile, RNase, DNase, Pyrogen free