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Radiolabeling of HYNIC–annexin V with technetium-99m for in vivo imaging of apoptosis


Apoptosis is a critical factor in AIDS and other viral illnesses, cerebral and myocardial ischemia, autoimmune and neurodegenerative states, organ and bone marrow transplant rejection, and tumor response to chemotherapy and radiation. Improved methods to identify sites of apoptosis are increasing our understanding of the pathophysiology and treatment of these and numerous other human disorders. Here we describe the most used method for labeling annexin V, a protein with a high affinity for apoptotic cells in vitro, with technetium-99m (99mTc) as a radionuclide imaging agent that can localize and non-invasively quantify apoptosis in vivo when coupled with single-photon emission tomography. In this method, annexin V is first attached to the bifunctional chelator molecule hydrazino nicotinate (HYNIC). Once prepared, HYNIC–annexin V can be labeled with 99mTc, a widely available γ-radiation-emitting radionuclide, for intravenous injection in as little as 30 min without the need for specialized reagents or equipment.

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Figure 1: In vivo imaging of apoptosis by radiolabeling of annexin V with 99Tc.


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This work was supported in part by grants from the National Institutes of Health (CA-102348 to J.T. and F.B., and EB000898 to F.B.).

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Authors and Affiliations



J.T. co-developed in vitro laboratory methods and co-wrote the article. J.-L.V. developed HYNIC–annexin V into a clinical kit for SPECT imaging and co-wrote the article. H.W.S. co-invented the use of HYNIC–annexin V for in vivo imaging of apoptosis and co-wrote the article.

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Correspondence to Francis G Blankenberg.

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The authors declare no competing financial interests.

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Blankenberg, F., Vanderheyden, JL., Strauss, H. et al. Radiolabeling of HYNIC–annexin V with technetium-99m for in vivo imaging of apoptosis. Nat Protoc 1, 108–110 (2006).

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