This course takes a look at heat-induced antigen retrieval (HIAR) methods, which have greatly contributed not only to immunohistochemistry (IHC) but also for studying gene expressions using archived formalin-fixed and paraffin-embedded (FFPE) specimens. It reviews antigen-antibody reactions, mechanisms of chemical fixation, mechanisms of HIAR, HIAR in electron microscopy, and effects of diluents on antibodies in IHC.

At the completion of this course the reader will be able to:

1. Briefly discuss antigen-antibody reactions.
2. Discuss the different mechanisms of chemical fixation.
3. Recall the mechanisms of Heat Induced Antigen Retrieval (HIAR).
4. Discuss HIAR as it applies to immunoelectron microscopy.
5. Describe the effects of diluents on antibodies in immunohistochemistry.