Used in solid-phase oligonucleotide synthesis to introduce modified nucleosides into DNA strands. The 5-ethenyluridine moiety acts as a fluorescent analog, enabling detection and tracking of nucleic acid interactions in hybridization studies. The DMT (dimethoxytrityl) group provides protection at the 5'-end, allowing for stepwise chain elongation and yield monitoring during synthesis. The phosphoramidite group at the 3'-end ensures efficient coupling to the growing oligonucleotide chain. This reagent is particularly valuable in developing probes for diagnostic assays, studying DNA/RNA structure, and creating functional nucleic acids with enhanced photophysical properties.