Knock out same-time protein concentration and quality with Stunner

Importance of the Topic

Reliable, rapid assessment of protein concentration and aggregation state is critical in biologics research, bioprocessing, and quality control. Simultaneous quantification and size analysis save sample material and accelerate decision-making by revealing both concentration and colloidal stability before extensive downstream assays.

Objectives and Study Overview

This application note demonstrates the use of the Stunner platform to perform combined UV/Vis and dynamic light scattering (DLS) measurements on monoclonal proteins. The goal is to validate that Stunner can accurately determine protein concentration across a wide dynamic range (0.02–200 mg/mL) and detect aggregation in a single high-throughput workflow, measuring up to 96 samples in under an hour with only 2 μL per well.

Methodology and Instrumentation

Samples of nine proteins (insulin, lysozyme, RNase A, ovalbumin, conalbumin, aldolase, BSA, IgG, thyroglobulin) were reconstituted in PBS at 5–10 mg/mL. Each protein was loaded in octuplicate into the Stunner plate, which integrates:

• UV/Vis absorption spectroscopy (A280) with wavelength-specific Rayleigh scattering correction
• Dynamic light scattering for hydrodynamic diameter (0.3–1000 nm) and polydispersity index (PDI)
• Micro-volume microplate with 0.1 and 0.7 mm pathlength cuvettes

The Stunner Client software assigns analytes and buffers, applies extinction coefficients (E1%), and collects four 5-second DLS acquisitions per well.

Main Results and Discussion

Protein concentrations determined by A280 closely matched target values (e.g., BSA: 10.07±0.04 mg/mL; insulin: 5.21±0.02 mg/mL). DLS revealed monodisperse samples (PDI<0.1 for insulin and BSA) versus polydisperse or aggregated proteins (PDI>0.2 for RNase A, conalbumin, aldolase). Intensity and mass distributions differentiated monomeric peaks from higher-order species, confirming Stunner’s sensitivity to minor aggregates (~0.5% mass fraction).

Benefits and Practical Applications

• High throughput: Up to 96 measurements per hour with minimal user interaction.
• Sample sparing: Only 2 μL needed, no manual dilutions for concentrations up to 200 mg/mL.
• Comprehensive data: Simultaneous concentration, size distribution, and aggregation assessment.
• Compliance ready: 21 CFR Part 11 option for regulated environments.

Future Trends and Potential Applications

As biologic modalities expand to include nanoparticles, fusion proteins, and multispecific antibodies, integrating orthogonal quality metrics will become increasingly important. Future developments may include automated workflows with robotic liquid handlers, advanced multi-wavelength DLS, and AI-driven analytics to predict long-term stability and formulation interactions.

Conclusion

The Stunner platform delivers simultaneous, accurate protein quantification and colloidal stability analysis in a single, micro-volume, high-throughput experiment. Its combined UV/Vis and DLS capabilities streamline early-stage characterization, enabling faster go/no-go decisions and reducing material waste.