Used primarily as a protecting group reagent in oligonucleotide synthesis, especially in the production of DNA and RNA strands for research and pharmaceuticals. The 4,4'-dimethoxytrityl group is attached to the 5'-hydroxyl group of nucleosides to prevent unwanted reactions during chain assembly. Its strong UV absorbance allows for easy monitoring and purification of intermediates. After synthesis, the group can be selectively removed under mild acidic conditions, making it ideal for solid-phase synthesis used in automated DNA synthesizers. Also employed in the preparation of functionalized surfaces and probes for bioconjugation and diagnostic applications.