Chemical tools that report on processes in live cells are of increasing importance, e.g., DNA-centered processes such as DNA replication and repair.

Marc Greenberg and colleagues, Johns Hopkins University, Baltimore, USA, have synthesized 5-ethynyl-2’-deoxycytidine (EdC) and 5-ethynyl-2’-deoxycytidine triphosphate (EdCTP). These new reagents can be used in conjunction with fluorescent labeling as reporters of DNA replication, in vitro and in vivo. EdC incorporated into DNA was readily detected by using commercially available click reaction reagents.
The team believes that EdC could be used to explore the chemical mechanism of DNA demethylation, an important pathway in DNA replication.

• Intracellular Detection of Cytosine Incorporation in Genomic DNA by Using 5-Ethynyl-2’-Deoxycytidine
  L. Guan, G. W. van der Heijden, A. Bortvin, M. M. Greenberg,
  ChemBioChem 2011.
  DOI: 10.1002/cbic.201100353