3.2.2.20	-20°C, stored frozen in buffer containing 1 mg/ml bovine serum albumin, stable for more than 6 months	
3.2.2.20	-20°C, stored in 50% glycerol, undergoes complete inactivation in 3-4 weeks	
3.2.2.20	-70°C, buffer containing 20% glycerol, stable for long term storage	
3.2.2.20	-70°C, stable