Product Stability and Expiration
Below is Shenandoah’s position on expiration and storage guidelines published on Shenandoah documents.
- 12 months from date of receipt when stored at -20 to -80 ºC as supplied.
Date Received: ___________________
- 1 month when stored at 4 ºC after reconstituting as directed.
- 3 months when stored at -20 to -80 ºC after reconstituting as directed.
Lyophilization allows for long-term storage of protein with very little threat of degradation so Shenandoah’s lyophilized product has no official expiration date set on Shenandoah documentation. All of Shenandoah’s products are stored lyophilized in-house and are shipped to customers in lyophilized format (exceptions are Human TGF-beta 3 and monoclonal antibodies). Long-term stability studies have been performed with our oldest products and oldest production lots. In these select products tested, no loss of activity has been observed in data obtained year over year for 10+ years stored in lyophilized format at -80 ºC. Not all products have been tested over this time frame. A guideline of 12 months from the date of receipt has been set as a way to track how long the customer has had the product in their possession but does not mean that the protein has lost activity. Many proteins may be stable for much longer than these guidelines and Shenandoah recommends each protein be tested in individual assays to establish stability guidelines specific to each assay.
Once a product has been reconstituted, it is difficult to make a blanket statement about protein stability. Every protein is different +/- carrier proteins and at 37 ºC, 4 ºC, -20 ºC or -80 ºC. In an effort to play it safe, we recommend to only keep protein for 1 month in the refrigerator or 3 months in the freezer after reconstituting as directed. Many proteins may be stable for much longer than these guidelines and Shenandoah recommends each protein be tested in individual assays to establish stability guidelines specific to each assay.