3.2.1.86 -20°C, 6 months, no significant decline in activity 3.2.1.86 4°C, 2 months, purified enzyme, 60% loss of activity 3.2.1.86 isoenzyme A, 4°C, 1 year, sterile starting buffer, 0% loss in activity 3.2.1.86 isoenzyme B, -20°C, 2 months, sterile starting buffer, 50% loss of activity