Antigen Retrieval for Immunohistochemistry with Paraffin-Embedded Tissues Protocol Protocol used to for immunohistochemistry on paraffin-embedded sections. Based on use of microwave energy to effect antigen retrieval. The immunohistochemistry procedure, is for use of Biomeda's HistoScan kit based on a streptavidin-peroxidase/biotinylated second antibody detection system with 3-amino, 9-ethylcarbazole (AEC) as chromogen. Undoubtedly, other kits or home-made reagents will also work .
Unmasking Hidden Epitopes Using the Microwave Oven Protocol Several methods have been developed to "retrieve" antigens that have been masked by fixation. The principle behind using the microwave oven method described here is to use extended periods of heat to break some of the subcellular structures that block antibody access. Be aware that any of the antigen retrieval methods should be avoided wherever possible, because they may introduce artifactual false-positive staining.
Unmasking Hidden Epitopes Using the Pressure Cooker Protocol The principle behind the pressure cooker method described here is to use extended periods of heat to break some of the subcellular structures that block antibody access. This approach is appropriate for handling specimens on glass slides. The major advantages of the pressure cooker method are the ability to handle a large number of slides simultaneously, the convenience of using metal racks, and the avoidance of any hot spots that are found in the microwave.
Unmasking Hidden Epitopes with Proteases Protocol Fixation can mask epitopes. However, it is often possible to re-expose them using a gentle incubation with proteases, which removes obstructing structures and allows antibody access, as described here. Many proteases can be used for this procedure, including very crude preparations of proteases, such as pronase. However, using a better-characterized protease, such as trypsin, allows a more controlled reaction and better comparison between experiments.