This chemical is a specialized phosphoramidite reagent primarily used in the synthesis of oligonucleotides, particularly in molecular biology and genetic research. It serves as a key building block in the phosphoramidite method, a standard solid-phase approach for constructing custom DNA and RNA sequences. The propargyl-PEG3 moiety enables the introduction of a clickable alkyne group via a flexible PEG linker, facilitating post-synthetic modifications through copper-free or copper-catalyzed azide-alkyne cycloaddition (click chemistry). This is valuable for attaching fluorophores, biotin, or other labels to oligonucleotides, supporting applications in gene editing (e.g., CRISPR), diagnostics, therapeutic development, and hybridization probes. Its stability and reactivity ensure compatibility with automated synthesizers, allowing precise and efficient production of modified nucleic acids, including antisense oligonucleotides for gene targeting.