Vial caps will hold corning color-coded inserts. Lock into corning cryogenic racks for single-handed operation. Cap inserts and self-locking racks are sold separately below right. Note: do not Autoclave or immerse vials in liquid nitrogen. For storage under extreme conditions such as liquid nitrogen, use cryoflex tubing 03755-64. Warning: this product is not approved or intended for, and should not be used for medical, clinical, surgical or other patient oriented applications. Supplied sterile and certified non-pyrogenic polypropylene construction withstands temperatures to -196°c. Silicone washers or rubber O-Rings provide a secure seal.