Patent ID: 7655392

Claim:
A method of treating a red blood cell composition which contains a red blood cell concentrate in a buffered additive solution, comprising: (a) mixing a quencher with a base, wherein the quencher comprises a thiol group and an acid group, and is capable of quenching an undesired side reaction of a pathogen-inactivating compound with the red blood cells, (b) mixing the quencher and base of step (a) with the red blood cell composition, (c) mixing a pathogen-inactivating compound with the red blood cell composition, wherein the pathogen-inactivating compound contains a nucleic acid binding group and a functional group which is an electrophilic group or is capable of forming an electrophilic group, wherein the electrophilic group is capable of reacting with nucleic acid, wherein the molar ratio of the quencher to pathogen-inactivating compound is about 10:1 to about 400:1, wherein the quencher is in a final concentration following step (c) of about 2 mM to about 40 mM, and wherein the base is in a molar ratio with the quencher of at least about 1, so that the undesired side reaction is decreased in comparison with the treatment method of a red blood cell composition without mixing of the base with the quencher.