DECALCIFICATION ENDPOINT TESTING — EDUCATIONAL SOP TEMPLATE

Record: specimen ID/type and dimensions; fixation window; decalcifier concentration/lot/volume; start date/time and temperature; solution changes; downstream tests; endpoint method and acceptance criteria.

Recognized endpoint approaches:
- Radiography: validated imaging shows no residual mineral in the required region.
- Chemical calcium test: validated aliquot-based precipitation method for compatible acid solutions.
- Physical probing/flexibility: subjective and potentially damaging; use only if locally permitted.
- Weight or other analytical methods: use only with validation.

Workflow:
1. Confirm fixation and appropriate trimming.
2. Use sufficient fresh decalcifier.
3. Record solution changes and monitoring points.
4. Increase monitoring frequency near endpoint.
5. Remove promptly when criteria are met; rinse/neutralize per IFU/SOP.
6. Process using a validated schedule.
7. Document deviations and downstream limitations.

Escalate when endpoint is uncertain, the specimen is irreplaceable, tissue is unexpectedly friable, exposure exceeds the validated window, or sensitive testing is requested after unvalidated acid treatment.
