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Thymidine Analogues for Tracking DNA Synthesis
Health Institute and Eskitis Institute, Griffith University, Queensland 4107, Australia
Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
These authors contributed equally to the work.
* Author to whom correspondence should be addressed.
Received: 31 August 2011; Accepted: 8 September 2011 / Published: 15 September 2011
Abstract: Replicating cells undergo DNA synthesis in the highly regulated, S-phase of the cell cycle. Analogues of the pyrimidine deoxynucleoside thymidine may be inserted into replicating DNA, effectively tagging dividing cells allowing their characterisation. Tritiated thymidine, targeted using autoradiography was technically demanding and superseded by 5-bromo-2-deoxyuridine (BrdU) and related halogenated analogues, detected using antibodies. Their detection required the denaturation of DNA, often constraining the outcome of investigations. Despite these limitations BrdU alone has been used to target newly synthesised DNA in over 20,000 reviewed biomedical studies. A recent breakthrough in “tagging DNA synthesis” is the thymidine analogue 5-ethynyl-2′-deoxyuridine (EdU). The alkyne group in EdU is readily detected using a fluorescent azide probe and copper catalysis using ‘Huisgen’s reaction’ (1,3-dipolar cycloaddition or ‘click chemistry’). This rapid, two-step biolabelling approach allows the tagging and imaging of DNA within cells whilst preserving the structural and molecular integrity of the cells. The bio-orthogonal detection of EdU allows its application in more experimental assays than previously possible with other “unnatural bases”. These include physiological, anatomical and molecular biological experimentation in multiple fields including, stem cell research, cancer biology, and parasitology. The full potential of EdU and related molecules in biomedical research remains to be explored.
Keywords: DNA synthesis; EdU (5-ethynyl-2′-deoxyuridine); nucleoside analogues
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MDPI and ACS Style
Cavanagh, B.L.; Walker, T.; Norazit, A.; Meedeniya, A.C. Thymidine Analogues for Tracking DNA Synthesis. Molecules 2011, 16, 7980-7993.
Cavanagh BL, Walker T, Norazit A, Meedeniya AC. Thymidine Analogues for Tracking DNA Synthesis. Molecules. 2011; 16(9):7980-7993.
Cavanagh, Brenton L.; Walker, Tom; Norazit, Anwar; Meedeniya, Adrian C.B. 2011. "Thymidine Analogues for Tracking DNA Synthesis." Molecules 16, no. 9: 7980-7993.