May be stored at 4 degree C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degree C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Labeled with horseradish peroxidase (HRP). Sodium azide is a potent inhibitor of peroxidase and should not be added to HRP conjugates. HRP conjugates are sensitive to light.