1.14.99.26	-10°C or 0°C, overnight, complete loss of activity	
1.14.99.26	-20°C, Tris HCl buffer, pH 7.4, 0.05 M, 10% ethanol, 50% glycerol, 0.045 M dithiothreitol, 1 mM 2-mercaptoethanol, stable for 16 d