Compatibility of 5-ethynyl-2'F-ANA UTP with in vitro selection for the generation of base-modified, nuclease resistant aptamers.

A modified nucleoside triphosphate bearing two modifications based on a 2'-deoxy-2'-fluoro-arabinofuranose sugar and a uracil nucleobase equipped with a C5-ethynyl moiety (5-ethynyl-2'F-ANA UTP) was synthesized. This nucleotide analog could enzymatically be incorporated into DNA oligonucleotides by primer extension and reverse transcribed to unmodified DNA. This nucleotide could be used in SELEX for the identification of high binding affinity and nuclease resistant aptamers.