Detection techniques using antibodies often fail to work on PFA- or formalin-fixed, paraffin-embedded sections. Antigen retrieval methods can then, in some cases, enable specific antibody detection. They work by reversing some of the chemical modification of epitopes during fixation. These procedures will not help much with epitope loss due to denaturation during sample treatment, like hot paraffin embedding.
Types of retrieval methods
Heat treatment
- Mechanism: heat cleaves cross-links, exposes buried epitopes of proteins, protein unfolding/refolding
- Specific protocol 1: citrate buffer
- Specific protocol 2: Tris-EDTA buffer
Protease treatment
- Specific protocol 1: proteinase K
- Specific protocol 2: trypsin
Detergent treatment
- Specific protocol: SDS