Infrared spectroscopy of nucleoside and DNA-oligonucleotide conjugates labeled with carborane or metallacarborane cage

Borane clusters as potential infrared label for nucleic acids are proposed. The unique infrared absorption of BH bond of the boranes is located in the window of nucleic acids transparency (2400-2650 cm−1). Fourier transform infrared spectroscopy characteristics of several carborane (-C2B10H11) and metallacarborane [3-Co-(1,2-C2B9H11)]− containing nucleosides bearing the borane marker is provided; method for incorporation of these nucleoside conjugates into DNA-oligonucleotides is shown.