SYNTHESIS AND USE OF 4-HYDROXYPHENYL DERIVATIZED PHOSPHORAMIDITES IN THE SELECTIVE RADIOIODINATION OF OLIGONUCLEOTIDE PROBES

Synthetic oligonucleotides probes are nowadays readily available and widely used in the identification of specific gene sequence from bacteria, viruses, in the diagnostic of human genetic diseases as well as in the development of antisense therapy. Much effort has been devoted to the development of non radioactive probes, nevertheless the radioactive labelling is still extensively used for research purposes. In this study we propose a new and simple synthesis of 4-hydroxyphenyl-oligonucleotide conjugates which upon reaction with I-125 give rise to radiolabelled probes. We describe two types of phosphoramidite reagents which allow the selective incorporation of a 4-hydroxyphenyl group at a specific site of an oligonucleotide in the course of its chemical synthesis. The radioiodination step is fast and specific of the hydroxyphenyl group and shows a high incorporation yield.