Liquid stored substance of erythrocyte, additive for cryopreservation of erythrocyte, production of erythrocyte condensate and compound of cryopreservation substance of erythrocyte

PROBLEM TO BE SOLVED: To obtain an additive comprising an α-lipoic acid and/or its enantiomer and/or its derivative, useful for homologous and autologous erythrocyte concentration, showing effects on prolongation of storage period, functionality improvement and recovery of erythrocyte having nontoxicity. SOLUTION: This additive comprises a D,L-α-lipoic acid and/or its enantiomer and/or its derivative (e.g. dihydrolipoic acid) as an active ingredient and is useful for homologous and autologous erythrocyte concentration. The additive is useful for preserving erythrocytes in a liquid state at 4 deg.C. The additive is useful for preserving erythrocytes in a frozen state at -70 deg.C to -90 deg.C (glycerol method) and at -196 deg.C/-140 deg.C liquid nitrogen (vapor-phase Haes method). The concentration of the additive in a blood pack is 10 μmol to 1 millimol, especially 100 μmol. The use of the additive can avoid the change of blood viscosity and cell fluidity. The additive can retain its effects even after a long storage period of about 60 days and can maintain its effects even after freezing and melting.