SurePac Oligo RP MDi HPLC Columns

Importance of the topic

Therapeutic oligonucleotides and other nucleic acid-based modalities require robust, high-resolution analytical methods across R&D and QC workflows. Chromatographic columns optimized for oligonucleotide separations are central to reliably characterizing sequence integrity, identifying truncation and other impurities, and enabling sensitive LC-UV and LC-MS analyses. Columns that combine inert surfaces, pore accessibility for large polynucleotides, and chemical stability under demanding mobile-phase conditions reduce artefacts, improve reproducibility, and support method scalability from analytical to preparative stages.

Objectives and overview of the product

The document presents the Thermo Scientific SurePac Oligo RP MDi HPLC column family as a solution engineered for oligonucleotide and nucleic acid separations. The primary aims are to deliver high-resolution separations of oligonucleotides across a broad size range, protect analyte integrity during analysis, and provide robust, reproducible performance that scales from capillary/analytical LC to semi-preparative formats for purification or bulk analysis.

Methodology and stationary-phase characteristics

The columns employ a monodisperse, supermacroporous polymeric packing designed to combine high chromatographic efficiency with accessible pore structure for larger polynucleotides and intact nucleic acids. The polymeric stationary phase minimizes secondary interactions that commonly afflict silica-based phases when analyzing charged, polyanionic biomolecules. The packing chemistry and inert hardware are optimized for compatibility with LC-UV and LC-MS detection and for sustaining performance under elevated pH and temperature—conditions sometimes required for resolving closely related sequences or enhancing desolvation in MS interfaces.

Used instrumentation

Summary of available column formats and practical implications:

• Particle size: 2.5 μm monodisperse polymeric particles.
• Analytical dimensions: 2.1 × 20 mm, 2.1 × 50 mm, 2.1 × 100 mm (useful for rapid screening and higher resolving power respectively).
• Micro/capillary: 0.3 × 50 mm for low-flow LC-MS and sample-limited applications.
• Semi-preparative / preparative formats: 10 × 50 mm and 21.2 × 50 mm for method scale-up and purification workflows.
• Hardware: inert column surfaces and housings designed to minimize adsorption and carryover of oligonucleotides.

These formats support workflows from sensitive, low-flow LC-MS assays to higher-throughput LC-UV or semi-preparative purification runs.

Main results and discussion

Key functional outcomes claimed for the column family include:

• High-resolution separation performance that reliably resolves truncation products and closely related sequence variants while retaining resolving power for longer oligonucleotides and intact nucleic acids.
• Preservation of nucleic acid integrity through inert hardware and polymeric packing that reduce nonspecific adsorption and degradation risks during analysis.
• Robust quantitative performance under demanding conditions, including elevated pH and temperature, which can be required for some separation strategies or for improved MS compatibility.
• Reproducible peak shape, stable recovery, and minimal carryover across runs, supporting QC implementation and method transfer between laboratories.
• Scalability across column geometries enabling translation of analytical LC methods to semi-preparative purification without major changes in stationary-phase chemistry.

Discussion points of practical importance:

• The supermacroporous structure provides pore accessibility needed for larger nucleic acids while maintaining efficiency for smaller oligonucleotides; this dual capability reduces the need for multiple specialized columns when characterizing heterogeneous oligonucleotide products.
• Polymeric stationary phases typically show better stability at higher pH than silica-based chemistries, expanding the operational window for resolving challenging variants and for certain sample preparation workflows.
• Inert hardware and minimized secondary interactions are particularly critical when coupling to MS to prevent signal suppression or memory effects that impair quantitation and identification.

Benefits and practical applications

Practical advantages and use cases include:

• R&D characterization of synthetic oligonucleotides, antisense oligos, siRNA fragments, and related therapeutics where resolution of sequence-related impurities is essential.
• QC release testing and stability studies requiring reproducible retention, low carryover, and robustness under routine elevated-pH cleaning or method conditions.
• LC-MS workflows where minimized nonspecific adsorption and polymeric chemistry improve MS sensitivity and method robustness.
• Scalability from low-flow analytical assays to semi-preparative separations for purification or scale-up, simplifying method transfer and reducing development time.

Future trends and possibilities for application

Anticipated directions and opportunities where such column technologies will be valuable:

• Growing demand for chromatographic solutions tailored to larger and more diverse oligonucleotide modalities as therapeutics diversify (gapmers, conjugates, aptamers, LNP-associated oligos).
• Increased integration with high-resolution mass spectrometry and microflow UHPLC for improved sensitivity and throughput in impurity profiling and sequence confirmation.
• Development of orthogonal stationary phases and ion-pair-free mobile-phase strategies to reduce MS suppression and simplify method transfer between labs and vendors.
• Automation and inline purification solutions that leverage scalable column formats to accelerate process development and early-stage manufacturing.
• Further materials engineering to extend chemical stability, reduce carryover for highly sticky sequences, and tailor selectivity for modified nucleotides and conjugated species.

Conclusion

SurePac Oligo RP MDi columns represent a targeted solution for modern oligonucleotide analytics, combining polymeric, monodisperse supermacroporous packing with inert hardware to deliver high resolution, nucleic-acid-friendly separations and scalable formats. Their performance advantages—particularly stability at elevated pH, low carryover, and pore accessibility for larger molecules—address common analytical challenges in both R&D and QC environments and support LC-UV and LC-MS workflows as well as scale-up to semi-preparative applications.

References

Thermo Fisher Scientific. SurePac Oligo RP MDi HPLC column product information and specifications, 2026.