Fluorescent or Redox Labelling of DNA for Bioanalytical Applications

One of the attractive areas of applications of modified nucleic acids is bioanalysis and diagnostics. We focus mainly on fluorescent and redox labelling. We have developed several types of environment sensitive fluorescent labels, linked them to dNTPs and incorporated these to DNA and ON probes for studies of their hybridization, SNP typing, pH microenvironment and/or protein binding. Molecular rotors (GFP-like or Knovenagel adducts) were also used for sending of protein–DNA interactions as light-up probes. Moreover, Bodipy-linked nucleotides, molecular rotors sensitive to viscosity, were used as fluorescence life-time probes for labelling of DNA and for fluorescence-life-time-imaging microscopy. Modified fluorene label was used as solvatochromic label for sending DNA-protein interactions by visible color change. Labeling of DNA or ON probes by redox-active groups that can be oxidized or reduced on electrodes was one of the major fields of applications. We have designed and prepared a number of dNTPs bearing diverse redox labels (nitro- and aminophenyl, anthraquinone, benzofurazan, azidophenyl, phenothiazine etc.) and successfully incorporated them to ssONs. These redox-labeled ON probes were studied by electrochemistry and applied in bioanalysis for electrochemical detection or redox coding of nucleotides (hybridization, SNP typing, minisequencing etc.) in collaboration with the groups of M. Fojta (IBP Brno) and C. O’Sullivan (URV Tarragona).