Yes, I´ve had success with activated caspase-3 from Cell Signalling, but only after an antigen retrival treatment with 10 mM Sodium Citrate buffer pH 6.0, at sub-boiling temperature for 10 minutes

Thanks for these comments. I will try

Cleaved PARP (Asp214) is another one, which is suppose to work fairly well in paraffin-IHC.

http://www.cellsignal.com/product/productDetail.jsp?productId=5625

In our experience cleaved capase-3 works very well. We have also tried using PARP cleavage with very little success.

If you just want quantify apoptotic cells, then I would recommend a TUNEL assay. The roche kit is straightforward to use:

https://cssportal.roche.com/LFR_PublicDocs/ras/11684795910_en_12.pdf.

I have included also included an article on how to count the TUNEL+ cells.

We also use the cleaved Caspase-3 (Asp175) Antibody #9661-from Cell signaling . Just follow the protocol which is already optimized for you. Never had any background with this antibody on our paraffin tumor slides.