Versatile On-Support Phosphitylation Enables Efficient Oligonucleotide Functionalization

A new chemical toolkit unveiled in Nature Chemistry could make it easier to customize DNA and RNA molecules for diagnostics, therapeutics, and synthetic biology. Researchers led by A. Dasgupta and colleagues report a “on-support phosphitylation” strategy that functionalizes oligonucleotides while they are still attached to a solid phase. The approach targets a persistent bottleneck in oligonucleotide engineering: reliably installing chemical handles without sacrificing yield, sequence integrity, or scalability.

The method begins by generating a reactive phosphitylating intermediate directly on the support material. Instead of completing the full oligonucleotide synthesis and then performing multiple solution-phase modification steps, the team performs key chemistry while the growing or immobilized strand remains anchored. This design reduces the number of transfers and minimizes opportunities for side reactions that can degrade sensitive nucleic acid backbones.

Technically, the researchers integrate a phosphitylation step that introduces reactive phosphorus-based functionality at defined points on the oligonucleotide. Those newly formed groups then serve as docking sites for subsequent transformations, allowing the authors to attach diverse functional moieties in a controlled manner. Because the chemistry is executed on the solid support, the process can be tuned for different payloads while maintaining relatively consistent reaction conditions.

A core advantage is versatility. The authors demonstrate that the same on-support logic can support different end goals—ranging from installing linkers and conjugation-ready units to enabling further derivatization routes used in downstream applications. Importantly, the paper emphasizes compatibility with practical oligonucleotide formats, suggesting the workflow can be adopted without requiring completely new manufacturing pipelines.

From a mechanistic perspective, carrying out phosphitylation on the support likely improves effective contact between reagent and substrate. It also helps prevent diffusion-limited problems that can occur in solution-based derivatization, especially when reactive intermediates have short lifetimes. The strategy thus blends the precision of solid-phase synthesis with the functional flexibility of phosphityl chemistry.

For viral science news audiences, the headline implication is clear: more efficient oligonucleotide functionalization can accelerate the construction of nucleic-acid tools. Whether these are used to probe viral genomes, map immune targets, or deliver sequence-specific therapeutics, better conjugation control translates into faster iteration cycles and potentially more reproducible products.

The authors report conditions that yield functionalized oligonucleotides with the desired chemical features and suitable overall performance for further processing. While the paper is rooted in synthetic chemistry, its downstream impact could extend to any field where oligos must be engineered with high fidelity.

Published in 2026, the study is linked to DOI 10.1038/s41557-026-02214-6 and positions on-support phosphitylation as a broadly applicable strategy for constructing functional nucleic-acid conjugates with improved practicality.