Alkaline CPD and the preservation of RBC 2,3-DPG.

Background: Concentrations of 2,3-DPG decline rapidly in the first week of RBC storage because of the low pH of conventional storage solutions. Alkaline additive solutions, which can preserve RBCs for up to 11 weeks, still do not preserve 2,3-DPG because the starting pH is below 7.2.