Organ and tissue preservation solutions having improved stability are disclosed. The solutions are comprised of two separate solutions. The first solution, Solution A, is comprised of a balanced salt solution that is stable in solution at a pH of 7.0 or above. A second solution, Solution B, is comprised of an aqueous solution containing L-glutathione and/or cysteinylglycine, a sugar such as D-glucose, L-Arginine, a reducing agent such as ascorbic acid and water at a pH of below 7.0, preferably from about 3.0 to 5.0. The two Solutions are then mixed together at the point of use and the pH adjusted to about 7.3 resulting in the organ and tissue preservation solution having improved stability. Preferably, solution A has a pH of about 7.6 and solution B has a pH of about 5.0. The present invention is also comprised of kits 20 that contain the two Solutions in two separate containers 22, 24. In an alternate embodiment, the sugar can be in Solution A.