Achieving consistent SEC performance through the use of 3 μm, 550 Å monodisperse media in novel bioinert column hardware

Importance of the Topic

Size exclusion chromatography (SEC) plays a central role in separating biomolecules by size, enabling accurate aggregate detection and molecular characterization. Advances in column media and hardware coatings are critical for minimizing secondary interactions, improving recovery, and ensuring reproducible performance, particularly in high‐resolution analyses of large biomolecules such as viral capsids.

Objectives and Study Overview

This study evaluates the novel Thermo Scientific SurePac Bio 550 SEC MDi 3 µm column packed with 550 Å monodisperse silica media in bioinert hardware. Key goals include assessing sample recovery, lot‐to‐lot reproducibility, separation efficiency, and calibration linearity for proteins and polymers.

Methodology and Instrumentation

• Chromatographic method: Isocratic SEC with UV detection at 280 nm and refractive index detection for PEG/PEO. Mobile phase: 50 mM phosphate buffer containing 300 mM sodium chloride, pH 6.5; flow rate 0.35 mL/min; column compartment temperature set to 30 °C; injection volumes 1–20 µL.
• Samples: Blue dextran, 4‐aminobenzoic acid, albumin, thyroglobulin, PEG/PEO standards, viral capsids and proteins prepared according to manufacturer instructions.
• Instrumentation: Thermo Scientific Chromeleon 7.3.2 CDS software; SurePac Bio 550 SEC MDi 3 µm column (4.6×150 mm) and prototype column in conventional stainless steel hardware, both with proprietary hydrophilic bioinert coatings.

Key Results and Discussion

• Monodisperse particle technology provided narrow particle size distribution, reducing batch‐to‐batch variability compared to polydisperse media.
• Van Deemter optimization identified an optimal linear velocity (~2.1 cm/min; 0.35 mL/min) for balancing efficiency and resolution.
• Bioinert hardware achieved near 100% first‐injection recovery, outperforming conventional stainless steel columns and minimizing secondary interactions.
• Lot‐to‐lot assessment across three media batches near specification limits demonstrated consistent retention times and resolution, confirming reproducible column performance.
• Calibration curves for PEG/PEO (molecular weight vs. elution volume) exhibited R²>0.98, while combined protein and polymer calibration based on hydrodynamic radius (4–30 nm range) showed R²>0.96.

Benefits and Practical Applications

The SurePac Bio 550 SEC MDi columns offer enhanced recovery and reproducibility, facilitating reliable characterization of macromolecules such as adeno‐associated viruses, therapeutic proteins, and polymer standards. Their consistent performance simplifies method transfer and supports high‐throughput QC in biopharmaceutical and research laboratories.

Future Trends and Opportunities

Emerging directions include further miniaturization of particle sizes, integration with multi‐detector arrays (e.g., MALS, DLS), development of advanced surface chemistries for broader biomolecule compatibility, and real‐time automated monitoring of bioprocess streams.

Conclusion

SurePac Bio 550 SEC MDi 3 µm columns with monodisperse 550 Å silica and bioinert hardware deliver robust, high‐resolution SEC separations with excellent recovery and lot‐to‐lot consistency, making them a valuable tool for accurate macromolecular analysis.

References

• Ma K, Ashworth J, Nieves V, Koontz A, Bechler S. Size-exclusion chromatography of adeno-associated viruses with the SurePac Bio 550 SEC MDi column. Application Note 003089. Thermo Fisher Scientific; 2024.