Organ and tissue preservation formulations with improved stability shelf life are provided by separating the formulation into a first solution having a pH of at least 7 and a second solution having a pH of less than 7. The first solution includes components with improved stability when stored at a pH of 7.0 or above, and the second solution includes components with improved stability when stored at a pH below 7.0. The first solution includes water, a balanced salt solution, a sugar, and L-arginine at a pH of at least 7.0. The second solution includes water, ascorbic acid, and reduced glutathione at a pH of less than 7.0 and preferably from pH 6.9 to about pH 2.8. During use, the first and second solutions are mixed to form a final formulation that can be used at a physiological pH to preserve the function of the tissue or organ.
