o-Xylylene N,N-diethylphosphoramidite is a difunctional specialty phosphoramidite reagent used in automated solid-phase synthesis of oligonucleotides. It introduces an o-xylylene linker or spacer, enabling the creation of branched, dimeric, or modified nucleic acid structures. These are widely applied in genetic research, diagnostics, and therapeutic development, including antisense therapy and gene editing technologies like CRISPR. Its design supports the formation of stable phosphoramidite bonds during synthesis, facilitating production of high-purity nucleic acids for biomedical applications.