Used in solid-phase oligonucleotide synthesis, particularly for introducing modified bases in DNA sequences. Enables the incorporation of thioacetyl-protected exocyclic amines, offering selective protection during synthesis. Provides improved coupling efficiency and stability in automated DNA synthesizers. Commonly applied in the production of antisense oligonucleotides, primers, and probes where precise modification control is required. The thioacetyl group can be removed under mild deprotection conditions, minimizing damage to the synthesized strand.