3.1.3.18	-20°C, 4 weeks, no significant loss of activity	
3.1.3.18	-20°C, stable at least 6 months	
3.1.3.18	-80°C, as an ammonium sulfate paste, few months, loss of activity	
3.1.3.18	4°C, 5% glycerol, 0.5 M NaCl, no loss in activity after several months	
3.1.3.18	4°C, 50 mM KCl, 2 mM MgCl2, 2.5 mg/ml bovine serum albumin, 3 weeks, 50% loss of activity