UNIT 21.4 Immunohistochemistry

  1. Florence Hofman

Published Online: 1 AUG 2002

DOI: 10.1002/0471142735.im2104s49

Current Protocols in Immunology

Current Protocols in Immunology

How to Cite

Hofman, F. 2002. Immunohistochemistry. Current Protocols in Immunology. 49:21.4:21.4.1–21.4.23.

Author Information

  1. University of Southern California, Los Angeles, California

Publication History

  1. Published Online: 1 AUG 2002
  2. Published Print: JUN 2002

This is not the most recent version of the article. View current version (18 NOV 2013)


This unit describes several methods for localizing specific antigens in various tissue and cell preparations using immunohistochemistry (IHC). Protocols describe preparation of suitable material for IHC including fresh, unfixed, frozen tissue specimens; unfixed cells, either freshly isolated or from suspension or adherent cultures, or fixed, paraffin-embedded tissue sections. By careful selection of reagents, it is possible to detect two antigens simultaneously. For antigens that are sensitive to fixative, it may be necessary to unmask the antigen by a new technique called “antigen retrieval”. If there is cross-reactivity between the secondary antibody and antigens present in the target cells or tissue, the secondary antibody can be preabsorbed. The different IHC protocols are represented schematically and summarized in a table, which also lists advantages and disadvantages of each approach. Causes of background staining and ways to eliminate it are also discussed.