1.1.5.4	-15°C, 24 h, 70% loss of activity	
1.1.5.4	-20°C, 0.3 M potassium phosphate buffer, pH 6.6, about 20% loss of activity after 2 weeks	
1.1.5.4	0°C, 24 h, 50% loss of activity	
1.1.5.4	when frozen, the activity is stable for several months	
1.1.5.4	when stored on ice, the half-life is approximately 120 h, important stabilizing conditions for storage on ice are the presence of EDTA and EGTA. the presence of glycerol, and pH 6. The presence of Mg2+ and Ca2+ has a destabilizing effect