A processing run is interrupted by a power outage for one hour after 2 hours 20 minutes have elapsed. What is the recommended action for the tissue?

• A. The tissue should be embedded
• B. The tissue should be re-fixed
• C. The tissue should be decalcified
• D. The tissue should be reprocessed from the beginning

Answer: (A)

During processing, tissue moves through fixation, dehydration, clearing, and paraffin infiltration. If a run is interrupted by a power outage, the key decision is whether paraffin infiltration has been completed. If infiltration has reached its final stage, the tissue should be embedded to form a solid block for sectioning, which preserves morphology and allows reliable microtomy even after a brief outage. Re-fixation would undo work already done, decalcification is only for mineralized tissues, and reprocessing from the beginning is only needed if infiltration wasn’t completed. In this scenario, embedding is the appropriate next step.