Frequently Asked Questions - Storage

How long are cryopreserved hepatocytes viable in liquid nitrogen?

When stored at the proper storage conditions (< -150° C), the cytochrome P450 enzyme systems remain unchanged after more than 5 years of storage.

Can I store cryopreserved hepatocytes in the cryoshipper?

No, the cryoshipper is not intended for storing cryopreserved hepatocytes. Upon receiving your shipment the cryopreserved hepatocyte vials must be removed and stored at temperatures less than -150°C.

How should I store the cryopreserved human renal proximal tubule cells?

The cells should be stored in liquid nitrogen – vapor phase < -150° C.

How do I store microsomes, S9, hepatocytes or media?

Media: (2° to 8° C) Do not freeze media. Storing media refrigerated maximises shelf life.

Antibiotics: (-15° to -25° C) Do not store in refrigerator. Avoid storage in "Frost-Free" freezer as temperature cycles can damage product.

Microsomes/S9: (-70° to -90° C) Store in mechanical freezer. Limit number of freeze/thaw cycles.

Hepatocytes: (< -150° C) Store in vapor phase of liquid nitrogen freezer. Do not allow product to thaw until ready for use. Do not store in liquid phase of liquid nitrogen freezer or Dewar type flask.

How long can I store microsomes and S9?

These products should always be stored in an ultracold freezer at temperatures < -70° C. Stored under these conditions, the cytochrome P450 enzyme systems are remarkably stable, showing little, if any, loss of activity after storage for more than 5 years. However, some of the phase II enzyme systems, particularly those in S9 such as N-acetyltransferase, are not stable even at -70° C, and lose significant activity within a matter of weeks or months.