2.3.1.39	-10°C, several weeks	
2.3.1.39	-20°C, 2-4 months	
2.3.1.39	-20°C, frozen in liquid nitrogen, several months	
2.3.1.39	-20°C, potassium-phosphate buffer, pH: 7.0, 1 mM dithiothreitol, 0.5 mM EDTA, 15% v/v glycerol	
2.3.1.39	-80°C, stable in the presence of glycerol