Used in the synthesis of DNA and RNA oligonucleotides for fluorescent labeling. Enables attachment of carbazole-based fluorophores to nucleic acid strands, enhancing detection sensitivity in molecular diagnostics and bioimaging. Particularly useful in developing probes for real-time PCR and fluorescence in situ hybridization (FISH). Stable under standard solid-phase synthesis conditions, allowing efficient incorporation into automated oligonucleotide synthesis workflows.