PROBLEM TO BE SOLVED: To provide a thrombocyte preservative effective for suppressing the lowering of thrombocyte function in the preservation of thrombocyte for thrombocyte transfusion and suppressing the side effect after transfusion and provide a preservation method and preserved thrombocyte. SOLUTION: A solution of a polyphenol is added to a preserved thrombocyte liquid to a concentration of 0.001-0.05 wt.% (10-500 ppm) or thrombocyte is preserved in a polyphenol solution of the above concentration. Polyphenol suitable for the purpose is (-)-epigallocatechin-3-O-gallate (EGCg), (-)-gallocatechin gallate and (-)-epicatechin gallate. COPYRIGHT: (C)2007,JPO&INPIT
