Used in solid-phase oligonucleotide synthesis, this phosphoramidite derivative enables the site-specific incorporation of deoxyxanthosine into DNA strands. Deoxyxanthosine acts as a structural analog of deoxyguanosine, making it valuable for studying DNA base pairing, mismatch repair mechanisms, and mutagenesis. It is particularly useful in biochemical and biophysical studies where altered hydrogen bonding patterns are needed, such as in the analysis of nucleic acid stability and polymerase fidelity. Its application extends to the development of modified aptamers and functional nucleic acids with tuned binding or catalytic properties.