Cryo Vials, External Thread, 4.5mL Round Base, case/500

4.5mL Externally-Threaded CryoVials features a round base, 12mm OD x 90.5mm. Cryo vials are designed for storage of samples as low as -196°C*. DNase, RNase, and Pyrogen-free. Radiation sterilized. Polypropylene vials feature a large white frosted labeling area, silk screen graduations, and a leak-proof HDPE cap. Skirted base vials have an internal flat bottom. Star base and round base vials have an internal U-shaped bottom. Self-standing star base vials are designed for one-handed use with a support rack. *Not recommended for use in the liquid phase of liquid nitrogen. (Can be used in vapor phase of liquid nitrogen.)