Synthesis of oligonucleotide probes containing 2'-deoxy-2'-fluoronucleosides for cleavage of RNA by RNase H

Modified oligodeoxyribonucleotides containing 3'-terminal 2'-deoxy-2'-fluorouridine (UF) or 2'-fluorothymidine (TF) were successfully applied for specific RNA hydrolysis by RNase H from E. coli. The nonanucleotides d(CACCGCGCTF) and d(CACCGCGCUF) were synthesized using the phosphoramidite solid support method. The modified nucleosides were immobilized on the CPG support and provided the starting nucleoside residues. Model experiments were carried out using the 5S RNA from E. coli ribosomes and its 1-41 fragment. It was found that the use of this type of modified probes did not decrease neither the efficiency nor the specificity of the RNase H reaction.