2.6.1.15	-20°C, in 30-50 mM potassium phosphate buffer, pH 7.2, 1 mM 2-mercaptoethanol, at least 7 weeks	
2.6.1.15	0-5°C, in 30-50 mM potassium phosphate buffer, pH 7.2, 1 mM 2-mercaptoethanol, little or no loss of activity for 1-2 weeks, in the absence of mercaptoethanol inactivation within 1-2 days	
2.6.1.15	24-26°C, 20% loss of activity of purified enzyme in 3 days	
2.6.1.15	4ºC, 10 mM potassium phosphate, pH 7.2, 10% glycerol, 1 mM 2-mercaptoethanol, 0.01 mM pyridoxal 5'-phosphate, 3 months