1.6.2.5	-15°C, can be stored as lyophilized powder for at least 3 months	
1.6.2.5	4°C, 0.4 M Tris-HCl, pH 8.0 purified concentrated enzyme is stable for approximately 2 weeks, gradual loss in activity can be restored by addition of glutathione to a final concentration of 0.0001 M, partially purified enzyme is stable for approximately 1 month