5.3.3.6	-20°C, protein concentration 1 mg/ml, little loss of activity after 60 days	
5.3.3.6	-80°C, protein concentration 10 mg/ml, less than 10% loss of activity after 6 months	
5.3.3.6	0°C, protein concentration 1 mg/ml, little loss of activity after 6 days