Protein Aggregation & Stability Testing
Early detection of aggregation and conformational changes in your biopharmaceuticals. Solution-state analysis reveals stability issues before they become problems.
Why Aggregation Testing Matters
Critical quality attribute: Protein aggregation affects safety, efficacy, and immunogenicity. Regulators require demonstration of aggregate control throughout product lifecycle.
Safety Concerns
Aggregates can trigger immune responses. Even sub-visible aggregates may cause immunogenicity issues in patients.
Efficacy Impact
Aggregated protein may have reduced or altered biological activity. Maintaining monomeric state is often critical for function.
Product Stability
Aggregation can progress during storage. Early detection enables formulation optimization before scale-up.
What We Detect
Early Oligomers
- Dimer formation
- Higher-order oligomers
- Reversible self-association
- Concentration-dependent behavior
Aggregation Onset
- Aggregation nucleation
- Aggregate size growth
- Fractal aggregate structure
- Aggregation kinetics
Conformational Changes
- Unfolding detection
- Domain rearrangement
- Flexibility changes
- Stress-induced changes
Advantages Over Other Methods
Earlier Detection Than DLS
Solution scattering can detect subtle changes in particle interactions and early oligomer formation that may not significantly affect hydrodynamic diameter.
Shape Information
DLS gives only size. We provide shape information — distinguish compact aggregates from extended oligomers.
Lower Aggregate Levels
Sensitive to aggregation at levels where SEC may show clean profiles. Detect changes before they become visible by other methods.
Native Conditions
No separation column, no dilution. Analyze your protein exactly as formulated, at relevant concentrations.
Technical basis: Our analysis uses Small-Angle X-ray Scattering (SAXS), which provides ensemble-averaged structural information on all species in solution. Learn more →
Applications
Formulation Development
Screen buffer conditions, pH, ionic strength, and excipients. Identify formulations that minimize aggregation propensity.
- Buffer optimization
- Excipient screening
- Surfactant effects
- pH stability range
Accelerated Stability
Monitor structural changes under stress conditions. Predict long-term stability from short-term studies.
- Thermal stress
- Mechanical stress (agitation)
- Freeze-thaw cycling
- Light exposure
Long-Term Stability
Track aggregation state at stability time points. Verify structural integrity over shelf life.
- Real-time stability
- Structural trending
- Specification verification
- Expiry determination support
Lot Release
Verify each batch meets structural specifications. Compare against reference standards.
- Batch consistency
- Release specifications
- Trending across lots
- Out-of-spec investigation
Comparability
Demonstrate structural equivalence after process changes. Support CMC variations.
- Manufacturing changes
- Site transfers
- Scale-up validation
- Supplier changes
Investigation Support
Investigate OOS results or stability failures. Understand root cause of aggregation events.
- Deviation investigation
- Complaint analysis
- Root cause analysis
- Corrective action support
Parameters We Report
Size & Mass
- Radius of gyration (Rg)
- Molecular weight from scattering
- Oligomeric state
- Aggregation number
Shape
- Pair distance distribution P(r)
- Maximum dimension (Dmax)
- Shape classification
- Envelope reconstruction
Interactions
- Second virial coefficient (B22)
- Attractive/repulsive interactions
- Concentration dependence
- Aggregation propensity
Flexibility
- Kratky analysis
- Flexibility assessment
- Disorder detection
- Domain dynamics
Biologic Types
We characterize aggregation and stability for various biopharmaceutical modalities:
Monoclonal Antibodies
IgG aggregation, Fab/Fc domain stability, concentration-dependent self-association.
Fusion Proteins
Fc-fusion stability, linker flexibility, domain organization under stress.
Peptide Therapeutics
Peptide oligomerization, fibril formation, concentration-dependent behavior.
Enzymes
Enzyme stability, activity-related conformation, storage stability.
Vaccines
Antigen stability, adjuvant interactions, formulation optimization.
Gene Therapy Vectors
Viral vector aggregation, capsid integrity, storage conditions.
Industrial Service Standards
cGMP Available
cGMP-compliant analysis available for specific sample types (not always possible — please inquire). 21 CFR Part 11 compliant data management.
Turnaround
Timelines discussed per project based on sample complexity and current capacity. We aim to meet your project deadlines where possible.
High-Throughput Option
Screen multiple formulations or time points efficiently. Automated sample handling.
Expert Interpretation
Clear reports with actionable conclusions. Root cause analysis and recommendations.
Case Study: Protein Aggregation Monitoring
Alpha-Synuclein Aggregation Pathway
Comprehensive study of protein aggregation from monomers through oligomers to mature fibrils. Demonstrates sensitivity to early aggregation intermediates.
- Monomer characterization
- Oligomer detection and sizing
- Fibril structure determination
- Aggregation kinetics
Additional publications on protein aggregation characterization:
Request Aggregation Testing Services
Contact us to discuss your protein stability characterization needs. We'll help design the right study for your development stage.
Sample requirements: 50-100 µL at 1-10 mg/mL (typical). Lower concentrations possible depending on molecular weight.
Formulation screening: We can analyze multiple conditions in parallel for efficient screening.