1.1.1.67	-10°C, 1 month, 50% loss of activity	
1.1.1.67	-16°C, 0.02 M sodium acetate buffer pH 6.0, 1 mM 2-mercaptoethanol, several weeks	
1.1.1.67	-20°C, 10 mM dithiothreitol, 45 days	
1.1.1.67	3°C, crystalline enzyme in ammonium sulfate, 2 months	
1.1.1.67	4°C or 20°C, enzyme loses approximately 60% of its specific activity after storage for 3 weeks in presence of 1 mM DTT, without DTT the same loss is observed after 2 days	
1.1.1.67	4°C, 1 month