In Situ Detection of Apoptosis by the TUNEL Assay: An Overview of Techniques

  • Deryk T. LooEmail author
Part of the Methods in Molecular Biology book series (MIMB, volume 682)


Apoptosis, or programmed cell death, plays an important role in normal development and homeostasis of adult tissues. Apoptosis has also been linked to many disease states, including cancer. One of the biochemical hallmarks of apoptosis is the generation of free 3′-hydroxyl termini on DNA via cleavage of chromatin into single and multiple oligonuleosome-length fragments. The TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay exploits this biochemical hallmark by labeling the exposed termini of DNA, thereby enabling visualization of nuclei containing fragmented DNA. This review outlines the general method for in situ TUNEL staining of cultured cells and tissue sections, and highlights recent improvements in the technique and limitations of the assay.

Key words

Apoptosis Necrosis TUNEL DNA fragmentation 


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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.MacroGenics, IncSouth San FranciscoUSA

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