1. Place five-micron thick tissue sections on glass slides.
2. Deparaffinize and rehydrate sections as usual.
3. Cover sections with Protease XXV solution and digest for 10 minutes at 37°C.
4. Wash sections in PBS for 2 x 5 minutes.
5. Block endogenous peroxidase as usual.
6. Wash sections in PBS for 2 x 5 minutes.
7. Block nonspecific sites with normal serum as usual.
8. Place optimally diluted primary antibody on the sections (incubation time and temperature for a given set of experimental conditions should be determined by the investigator).
9. Wash sections in PBS for 2 x 5 minutes.
10. Remaining procedure is same as routinely performed in your laboratory.