Chen, M.; Gothelf, K. V.
Org. Biomol. Chem. 2008, 6, 908–911, doi: 10.1039/b717664c
Centre for DNA Nanotechnology at iNANO and Department of Chemistry, University of Aarhus, Langelandsgade 140, DK-8000 Arhus C, Denmark
The reaction of phosphorothioates in DNA with 2-bromoethylammonium bromide results in S-2-aminoethyl phosphorothioates, which can rearrange to N-(2-mercaptoethyl)phosphoramidates providing a facile method for the generation of site-specific thiol labeling of DNA sequences. The applicability of this method was demonstrated by conjugation of the thiolated DNA sequence with Na-(3-maleimidylpropionyl) biocytin and Alexa Fluor 546 C5-maleimide.