Hospitals maintain allografts in ultra-cold refrigerators between -80 C to -40 C as this qualifies for a shelf life of up to 5 years. In accordance with the American Association of Tissue Banks (AATB) standards, those allografts can be stored above -40 C and below -20 C for 72 hours and be returned to long-term storage.
Many facilities use dry ice to transport the allografts from storage to the surgical suite. Dry ice must be purchased, is classified as dangerous, and cannot be stored, as it will go back to the gaseous state quickly.
TCP has been using an ultracold -21 Centigrade Phase Change Material (PC-21) to maintain allograft for the United States Military and civilian hospitals for transport to the surgical suite. The PC-21 is a nontoxic reusable Phase Change Material (PCM) capable of being stored for years without losing efficacy. A graph of those results from our hospital is shown above. In summary, the allograft payload was maintained below -21 C in our tote for 29 hours.