1. Deparaffinize and re-hydrate sections as usual.
2. Add one bottle of HIER Buffer H in to a PT Module tank; dilute to 1.5 liters with deionized water (1:100 dilution).
3. Measure and document pH with calibrated pH meter per accreditation guidelines (optional).
4. For antigen retrieval, pre-heat the PT Module (PTM) to 85°C and immerse the slides mounted on the Autostainer rack into the PT Module tank.
5. Pre-warm the buffer to 98°C and hold for 20 min.
6. Cool slides in the PT Module to 85°C. Cool further to RT in TBST buffer for at least 5 min. Ensure slides remain moist.
7. Keep all the slides in buffer until the slides are loaded on to the Autostainer.