Cryopreservation of Platelets.

Platelets are transfused to stop bleeding from trauma or during surgery, and to prevent bleeding that may occur in various diseases, including cancer, bone marrow failure, and chronic blood disorders due to low or dysfunctional platelets. The platelet supply is often unpredictable, leading to shortages in hospitals, blood centers, and the military. Cryopreservation offers a solution by extending platelet shelf-life and enabling stockpiling for emergencies, rare donor phenotypes, and use in remote locations. In this chapter, cryopreservation of platelets below -65°C using 5%-6% DMSO with reconstitution of thawed platelets in plasma is described. The procedure requires standard blood banking equipment and a -80°C freezer. Platelets are stored in a -80°C freezer, as liquid nitrogen storage is impractical. Cryopreserved platelets remain viable for up to 12 years when stored below -65°C. Thawing is straightforward, though resuspension in plasma or saline is required, and the shelf life after thawing is limited to 4-8 h.