Donated tissues are processed by laboratory personnel on the basis of their possible subsequent use. Processing takes place in laboratories certified class A and B.
Storage techniques will depend on the tissue type and are:
- Freezing (-800C). After processing, tissues are preserved at -800C without the use of cryopreservants, thereby eliminating cell components that could cause adverse recipient reactions on implantation. Bone tissue used as a filler in bone reconstruction as well as large bone segments are also preserved at -800C;
- Cryopreservation (-1600C). This is a long-term preservation technique that ensures that most of the cells' functions remain intact. After processing, the tissue is plunged into a cryopreservant solution. To avoid hyperosmolarity shock, which would damage cells and jeopardise their viability, tissues are first placed in polyethylene bags. The nitrogen vapour storage tanks are kept at a constant temperature. Tissue preserved in liquid nitrogen subsequently presents lower immunological responses. In fact, the histocompatibility receptors of thawed tissue previously stored at -1600C are considerably reduced;
- Freeze-drying. The freeze-drying plant, the method used and its quality control system all comply with Good Manufacturing Practices standards used in the production of sterile pharmaceuticals (Eudralex Vol. 4 Medical products for human and veterinary use: Good Manufacturing Practices – Annex 1 - Manufacture of Sterile Medicinal Products).