1.14.14.94	-70°C, 20% glycerol,1 mM dithithreitol, 3 days and 10 days, 50% resp. 100%	
1.14.14.94	-70°C, 50% losss of activity after 3 days	
1.14.14.94	-70°C, no loss of activity with highly purified preparations even after 4 years	
1.14.14.94	-70°C, rapid loss of activity	
1.14.14.94	-70°C, stable for 4 years