Bio Plas, 4030, G-Tube Premium Flat Top Microcentrifuge Tube, NaturalThe G-Tube® Flat Top Microcentrifuge Tube is virtually transparent and far exceeds the toughness of any microcentrifuge tubes. When the G-Tube Flat Top Microcentrifuge Tube cap is closed there will be an audible 'snap' that indicates a secure closure has been formed.Made of tough, clear, proprietary formulated polypropylene, G-Tube has the same chemical resistant quality as standard tubes, but they're sturdier and virtually transparent to give a better view. The flat top cap is easy to open and still provides a maximum secure seal. All three volumes are available in siliconized material. Siliconized G-Tubes are not recommended for autoclaving.The G-Tube is built for high impact usage and will withstand over 30,000 x G when spun. Thicker walls make this the tube of choice for extreme stress, high spinning speeds, autoclaving, boiling, chemical resistance and freezing. Will withstand temperature ranges of -80°C (-112°F) to 121 °C (250°F).Features:Made from high quality medical grade resinsRNase and DNase free. Human DNA free. Non-PyrogenicUltra low retention Lid Closure: The flat top lid forms an extra-tight seal that will not come open during processing. Yet, it's easy to open with thumb pressure or our handy MicroTube ToolBio Plas G-Tubes have a textured writing surface on top of the caps. The 1.5ml and 2.0 mL tubes have an additional textured writing surface on the side of the tubesGraduation: The 1.5ml tubes and 2.0ml tubes are graduated every 0.1mlBoilproofWill withstand speeds up to 30,000 X GEasy needle access through the piercing port in the exact center of the capAutoclavable at 250°F at 15 psi for 15 minutes.Withstand temperature ranges from -80°C to 121°C Unit of MeasurePack of 500 pcs.