Retrieved tissue

Must be placed at a temperature of between 0–10°C within 4 hours of retrieval.¹

Bacteriostasis

Freezing tissue to –20°C or colder within 24 hours of retrieval can be used as a bacteriostatic treatment.

Bone from living donors which is not frozen until 24–48 hours after retrieval must be subjected to terminal antimicrobial processing.

Long-term storage

Bone from living donors may be stored at –20°C or colder for up to 6 months or at  –40°C or colder for up to 5 years. Temporary storage of frozen living donor bone between –20°C and –40°C is limited to 6 months in total. Grafts stored at this temperature must then be transferred to –40°C or colder to give an expiry of up to a maximum of 5 years from donation.
Amnion preserved in low-concentration (50%) glycerol may be stored at –40°C or colder for up to 2 years.

Transportation and local storage

Must be transported and stored locally prior to clinical use, at –20°C or colder in order to have the designated expiry (specified above).

¹ As the tissue itself it taken directly from a living individual, setting temperature criteria for the tissue itself during this initial storage and transport is not feasible, therefore only the ambient temperature it must be kept at is specified.

Retrieved tissue

Must be placed at a temperature of between 0–10°C within 4 hours of retrieval.¹

Bacteriostasis

Freezing tissue to a temperature of –20°C or colder within 24 hours of retrieval (or up to a maximum of 72 hours of death) can be used as a bacteriostatic treatment.

Long-term storage

Frozen* tissue may be stored:
1. At –20°C or colder for up to 6 months.
2. At –40°C or colder for up to 5 years. Temporary storage of frozen musculoskeletal tissue between –20°C and –40°C is limited to 6 months in total. Grafts stored at this temperature must then be transferred to –40°C or colder to give an expiry of up to a maximum of 5 years from donation.

Cryopreserved** tissue:
At –135°C or colder to claim a 10-year expiry for all grafts to maintain a reasonable inventory of size-matched grafts (e.g. heart valves and menisci). Other cryopreserved tissues should have a 5-year expiry.

Glycerol-preserved tissue:
Skin preserved in high-concentration (>90%) glycerol may be stored at between 0–10°C for up to 2 years.

Freeze dried tissue:
Freeze-dried tissue may be stored at ambient temperature for up to 5 years. This includes freeze dried demineralised bone tissue mixed with a glycerol carrier

Decellularised Tissue:
Decellularised dermis tissue that has been terminally sterilised may be stored at colder than –40°C for up to five years, or at up to +40°C for up to two years.

Transportation and local storage

Frozen* tissues must be transported and stored locally prior to clinical use, at colder than –40°C if they are to retain their original expiry date. If they are stored locally at temperatures colder than –20°C or warmer than –40°C, the expiry date must be reduced to a maximum of 6 months or the balance of the original expiry date, whichever is lower.

Cryopreserved** tissues may be transported in the vapour phase of liquid nitrogen (–135°C or colder) or on dry ice (–79°C or colder). If tissues are transported on dry ice they should continue to be stored locally at –80°C or colder for a maximum of 6 months.

For the purposes of this guidance, the following definitions apply:

* Frozen tissue – Tissue stored at sub-zero temperatures, with ot without cryoprotectant.

** Cryopreserved tissue – Tissue preserved and stored at sub-zero temperatures using a cryoprotectant, either by controlled slow freezing or by vitrification.

¹ As the tissue itself it taken directly from a living individual, setting temperature criteria for the tissue itself during this initial storage and transport period is not feasible, therefore only the ambient temperature it must be kept at is specified.