Dive deep into Stunner’s light scattering

Significance of the Topic

Understanding particle size, molecular weight, and aggregation state is critical in biologics and gene therapy development. Combined spectral and scattering analysis delivers a complete biophysical profile and ensures sample integrity, supporting research, quality control, and formulation efforts.

Objectives and Study Overview

This technical note presents the principles of dynamic and static light scattering, and introduces the Stunner instrument with rotating angle dynamic light scattering RADLS. The goal is to show how RADLS and UV / Vis spectroscopy are integrated in a single workflow to characterize samples using as little as two microliters in under two minutes.

Methodology and Instrumentation

The note covers fundamental scattering regimes

• Rayleigh scattering for particles much smaller than the light wavelength with isotropic intensity and wavelength dependence
• Mie scattering for particles comparable to or larger than the wavelength with angle dependent intensity patterns

Classic dynamic light scattering DLS measures fluctuations in scattered light intensity to derive diffusion coefficients and hydrodynamic diameters via cumulants or regularization analysis. Static light scattering SLS measures average intensity to determine molecular weight concentration and radius of gyration through extrapolation to zero degrees using a Guinier plot. RADLS extends DLS and SLS by rotating the detector fiber around the sample, capturing seven angles to enable angle independent Z-average diameters and Rayleigh ratios. Stunner’s microfluidic plates use low absorbance plastic with fixed pathlength microcuvettes and automated sample pumping. Key instrument components include a xenon flashlamp for UV / Vis, dual lasers and a rotating detection fiber for light scattering, a photon counter, and proprietary analysis software following ISO 22412:2017 standards.

Key Results and Discussion

RADLS data processed across multiple angles yields an extrapolated Z-average hydrodynamic diameter independent of angle and highlights even rare aggregates. Combining hydrodynamic radius Rh and radius of gyration Rg reveals shape information via the Rg / Rh ratio. The workflow measures UV / Vis absorbance and seven‐angle scattering in about 90 seconds per sample, requiring only two microliters. Automated alignment steps ensure optimal beam overlap at each angle, supporting reproducible high throughput measurements.

Benefits and Practical Applications

Stunner with RADLS provides

• Low sample consumption for precious biologics lipid nanoparticles and viral vectors
• Rapid simultaneous concentration size and aggregation assessment
• High sensitivity to detect trace aggregates
• Structural insights through combined Rh and Rg analysis
• Seamless integration with automation using standard microplate format

This enables enhanced process monitoring, formulation screening, and quality control in research and manufacturing environments.

Future Trends and Potential Applications

Advances may include expanded angle ranges for deeper analysis of highly polydisperse systems, machine learning algorithms for pattern recognition in scattering data, integration with orthogonal biophysical methods such as mass photometry or capillary electrophoresis, and broader application to complex formulations including lipoproteins and extracellular vesicles.

Conclusion

By combining UV / Vis spectroscopy with rotating angle dynamic light scattering in a single microfluidic workflow, Stunner delivers rapid accurate and comprehensive biophysical characterization. This platform supports the growing demands of biologics and gene therapy development by providing critical size molecular weight and aggregation data in one high throughput instrument.