This document provides methods and materials for enhancing the storage capabilities of red blood cell preparations. For example, methods and materials for using CO2 to store red blood cells in a manner that (a) reduces the level of glucose or 2,3-DPG consumption of or reduces the level of 2,3-DPG production by a red blood cell preparation, (b) reduces the level of lactate formation by a red blood cell preparation, and/or (c) reduces the pH level of a red blood cell preparation are provided. Such methods and materials can result in prolonging the useful lifespan of the red blood cells of the red blood cell preparation. This document also provides methods and materials involved in prolonging useful storage of platelet preparations. For example, methods and materials for storing platelets in a manner that reduces platelet metabolism, that preserves platelet function, and/or that reduces the risk of bacterial contamination are provided.
