Electroactive labeling of DNA and PNA by osmium tetroxide complexes

Osmium tetroxide complexes (Os,L) are excellent tools for electrochemical DNA labeling due to facile modification of unpaired thymine residues under physiological conditions and to useful electrochemical properties of the Os,L-nucleic acid adducts. The labeling reaction can be performed in any biochemical or biological laboratory without any special requirements for equipment or expertise, making it widely accessible and versatile. In this work we introduced a technique of electrochemical “multicolor” DNA labeling with the Os,L, based on choice of ligands L influencing the label redox potential. Os,L labeling of PNA, which was performed for the first time, provided particularly high sensitivity of electrochemical detection, and together with specific recognition features of the PNA probes appears promising for applications in practical sequence-specific DNA sensing.

M. Fojta, P. Kostecka, M. Trefulka, L. Havran, and E. Palecek, "Multicolor" electrochemical labeling of DNA hybridization probes with osmium tetroxide complexes. Analytical Chemistry 79, 1022-1029, 2007.

E. Palecek, M. Trefulka, and M. Fojta, End-labeling of peptide nucleic acid with osmium complex. Voltammetry at carbon and mercury electrodes. Electrochemistry Communications 11, 359-362, 2009.