A chemical method for fast and sensitive detection of DNA synthesis in vivo
- *Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115; and
- ‡Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115
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Communicated by Howard Green, Harvard Medical School, Boston, MA, December 26, 2007 (received for review November 6, 2007)
Abstract
We have developed a method to detect DNA synthesis in proliferating cells, based on the incorporation of 5-ethynyl-2′-deoxyuridine (EdU) and its subsequent detection by a fluorescent azide through a Cu(I)-catalyzed [3 + 2] cycloaddition reaction (“click” chemistry). Detection of the EdU label is highly sensitive and can be accomplished in minutes. The small size of the fluorescent azides used for detection results in a high degree of specimen penetration, allowing the staining of whole-mount preparations of large tissue and organ explants. In contrast to BrdU, the method does not require sample fixation or DNA denaturation and permits good structural preservation. We demonstrate the use of the method in cultured cells and in the intestine and brain of whole animals.
Footnotes
- †To whom correspondence should be addressed. E-mail: asalic{at}hms.harvard.edu
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Author contributions: A.S. and T.J.M. designed research; A.S. performed research; A.S. analyzed data; and A.S. wrote the paper.
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The authors declare no conflict of interest.
- © 2008 by The National Academy of Sciences of the USA
