Used in solid-phase oligonucleotide synthesis as a non-nucleosidic phosphoramidite modifier to incorporate a specific azo dye moiety into synthetic DNA or RNA sequences. This reagent features a diisopropylphosphoramidite activating group for high-efficiency coupling, a 2-cyanoethyl protecting group on phosphorus, and a 4,4'-bis(4-methoxyphenyl)(phenyl)methoxy (MMTr)-protected aminoethyl linker connected to a phenyl ring bearing diazenyl groups derived from 2,5-dimethoxy-4-(4-nitrophenylazo)aniline. The structure enables precise attachment of the chromophoric or quenching group at the 5'-end or internal positions of oligonucleotides, supporting applications in fluorescence quenching, FRET-based probes, biosensors, DNA microarrays, real-time PCR, gene expression analysis, and diagnostic tools for genetic research and drug development. The protecting groups ensure stability and selective deprotection during automated synthesis cycles, facilitating high-throughput production of labeled custom sequences.