4.3.1.1	-20°C, pH 7.0, 2% 2-mercaptoethanol, several months, no loss of activity	
4.3.1.1	-20°C, stable for 1 month	
4.3.1.1	-20°C, stable for a few weeks	
4.3.1.1	-20°C, stable for several months	
4.3.1.1	-70°C stable over 3 months	
4.3.1.1	-70°C, stable for 1 month without addition of salts or glycerol	
4.3.1.1	2-mercaptoethanol and dithiothreitol protect enzyme against inactivation during storage	
4.3.1.1	4C, in the presence of various salts thiol compounds, or glycerol stable for 2 weeks	
4.3.1.1	4°C, loss of activity after 1 month independently of the presence of glycerol or MgCl2	
4.3.1.1	enzyme activity can be maintained by freezing up to 6 months in the ammonium sulfate precipitate