Method for preserving blood platelets

A method for preserving platelets for later direct transfusion into a patient, the method comprising:

• forming a preservation medium by mixing plasma comprising platelets with gelatin where a concentration of gelatin relative to the plasma in the resulting preservation medium is between 1.0% to 3.0%, this gelatin concentration causing the preservation medium to (a) be sufficiently fluent at about 37° C. to allow platelets to move within the preservation medium, (b) transition from the fluent state to a gelatinous state below 15° C., and (c) be sufficiently gelatinous below 5° C. to substantially prevent platelets from moving freely within the preservation medium;
• cooling the preservation medium to a temperature below 0° C.;
• and
• storing the preservation medium below 0° C. for at least 1 day at a pressure of at least 70 ATM.