Final answer:
The expiration date for tissue storage begins at Initial processing.
Step-by-step explanation:
The expiration date for tissue storage begins at Initial processing. Once the tissue is processed, it is given an expiration date based on factors such as the type of tissue, storage conditions, and any potential degradation over time. Final culture results, release date from quarantine, and reprocessing dates may be important for monitoring the quality and safety of the tissue, but they do not determine the initial expiration date.