Discloses a novel means for producing an artificial preservative solution-substituted platelet solution having platelet activation suppression performance, high platelet recovery performance and high plasma removal performance. The method for producing an artificial preservative solution-substituted platelet solution of the present invention uses a separation membrane having an average pore size of 0.1 m or more and less than 2.0 m on the surface in contact with the platelet solution under the condition represented by the following formula 1,-1Filtration step of cross-flow-filtering the platelet solution at an inlet wall shear rate of the filter plate to obtain a concentrated platelet solution and a mixing step of mixing the concentrated platelet solution with an artificial preservation solution to obtain an artificial preservation solution-substituted platelet solution .1.0 1011<(A B) / ( P) 2.5 1013(Pieces / (hr m2 Pa)) Equation 1 A: Platelet concentration contained in platelet solution (number / mL however, 8.0 107~ 200 107Pieces / mL) B: Filtration flow per area (mL / hr / m2) : Entrance wall shear rate (s-1) P: Viscosity of platelet solution (Pa s)血小板の活性化抑制性能、高い血小板回収性能及び高い血漿除去性能を有する、人工保存液置換血小板溶液を製造するための新規な手段が開示されている。本発明の人工保存液置換血小板溶液の製造方法は、下記式1で表される条件下、血小板溶液と接する面の平均孔径が0.1μm以上2.0μm未満の分離膜を用い、25~1500s-1の入口壁ずり速度で前記血小板溶液をクロスフロー濾過して濃縮血小板溶液を得る濾過ステップと、前記濃縮血小板溶液を人工保存液と混合して人工保存液置換血小板溶液を得る混合ステップと、を備える。1.0×1011<(A×B)/(γ×μP)≦2.5×1013(個/(hr・m2・Pa)) ・・・・式1 A :血小板溶液に含まれる血小板濃度(個/mL;ただし、8.0×107~200×107個/mL) B :面積あたり濾過流量(mL/hr/m2) γ:入口壁ずり速度(s-1) μP:血小板溶液の粘度(Pa・s)
