Cryogenic Vials are manufactured from polypropylene for storing biological material, human or animal cells at temperatures as low as -196 °C. Internal threads, external threads and round bottom, conical bottom, self-standing and non-standing varieties are available. The cap of internal thread cryogenic vial integrates a silicone o-ring to enhance sealing properties. Externally threaded vial has no o-ring but with external screw cap which reduces risk of contamination. All vials are nonpyrogenic and RNase- and DNase-free.