TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The preserving gas is gaseous oxygen (preferred), gaseous hydrogen, gaseous carbon dioxide, gaseous carbon monoxide, or water vapor. Preferred Composition: The gas/gas mixture has an oxygen concentration of 20-100 (preferably 40)%; and a temperature of 4-8 degrees C at the time of perfusing the organ. When the gas/gas mixture has an oxygen concentration of 40% then the perfusing step comprises perfusing the organ with the gas/gas mixture at a flow rate of 15-22 cc/minute and at a pressure of less than 22 mm Hg.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The method further comprises dissolving the preserving gas generated in step (a) in a liquid solvent to form a gas/liquid solution and where the perfusing step comprises perfusing the organ with the gas/liquid solution; mixing the preserving gas generated in step (a) in one or more gases to form a gas/gas mixture and where the perfusing step comprises perfusing the organ with the gas/gas mixture. The step for in situ generating a preserving gas is performed: electrochemically using an electrolyzer or an electrochemical oxygen concentrator; or by pressure swing adsorption or chemical oxygen release. When the organ is a pancreas, the preserving gas is gaseous oxygen, then the method further comprises mixing the preserving gas in ambient air to form a gas/gas mixture where the perfusing step comprises perfusing the organ with the gas/gas mixture. When the organ is many organs then the perfusing step comprises perfusing the organs simultaneously. In the method of pancreas preservation, the preserving gas is present in: a gas/liquid solution where the perfusing step comprises perfusing the pancreas with the gas/liquid solution; or a gas/gas mixture where the perfusing step comprises persufflating the pancreas with the gas/gas mixture; and the pancreas is a human pancreas. The persufflating step comprises persufflating the pancreas anterograde via cannulation of at least one artery or retrograde via cannulation of at least one vein; and persufflating the human/porcine pancreas through at least one ductal entry or both through at least one ductal entry and through at least one artery or vein. The cannulation comprises en bloc pancreaticoduodenectomy and/or splenectomy with division/cannulation of: aorta to include celiac trunk and superior mesenteric artery; or proximal splenic artery and superior mesenteric artery. The cannulation comprises en bloc pancreaticoduodenectomy and/or splenectomy with cannulation of inferior mesenteric vein or splenic vein. The cannulation comprises en bloc pancreaticoduodenectomy and/or splenectomy with cannulation of superior mesenteric vein or portal vein. Preferred Components: The means for in situ generating a preserving gas comprises a water electrolyzer or an electrochemical oxygen concentrator. The means for in situ generating a preserving gas comprises a water supply and means for feeding water, in a vapor phase, from the water supply to the electrochemical oxygen concentrator. The system further comprises means for diluting the preserving gas in ambient air to form a gas/gas mixture, the gas/gas mixture being used to form the gas streams; and housing, the organ container being removably mounted within the housing. The thermal control device comprises means for maintaining the contents of the organ storage container at 4-8 degrees C.