Identify and Characterize Particles in the Visible Size Range with Aura

Significance of the Topic

Characterization of visible and subvisible particles in parenteral drug formulations is critical for patient safety and regulatory compliance under USP 788 790 and 1046. Reliable detection prevents adverse immune responses and efficacy loss ensuring quality control throughout biologic cell and gene therapy development.

Objectives and Overview of the Study

This application note evaluates Aura Systems and Particle Vue Software for high-throughput detection and characterization of visible size range particles generated in various biologic processes. Standard polymer beads viral aggregates cellular clusters and fibrous contaminants serve as models to illustrate analytical performance and compositional identification.

Methodology and Instrumentation

The analysis combines backgrounded membrane imaging for accurate particle sizing with side illumination membrane imaging and fluorescent membrane microscopy for compositional insights. Calibration utilizes a microscopy reference slide across 96-well small-volume and 24-well large-volume plates.

• Aura and Aura CL particle analysis systems
• Particle Vue Software with proprietary detection algorithms
• Backgrounded membrane imaging BMI method
• Side illumination membrane imaging SIMI
• Fluorescent membrane microscopy FMM with nucleic acid and protein stains

Main Results and Discussion

• NIST ETFE particles exceeding 200 µm equivalent circular diameter were accurately sized and revealed three-dimensional structure via SIMI.
• Large cellular aggregates from CAR T therapies were detected clog-free and confirmed by Hoechst fluorescence which also identified trapped cell singlets.
• Extrinsic fibrous contaminants in cell therapy samples were distinguished from biological aggregates with combined brightfield and fluorescent imaging.
• AAV aggregates over 700 µm were measured without fluidic clogging and identified as proteinaceous using Thioflavin-T fluorescence.

Benefits and Practical Applications

Aura systems provide linear accurate sizing of particles up to several millimeters without channel clogging or image fragmentation. Fluorescent modalities enable specific compositional identification supporting robust quality control in biologic cell and gene therapy manufacturing workflows.

Future Trends and Opportunities

Integration of artificial intelligence for automated particle classification and real-time monitoring will enhance throughput and data interpretation. Expansion to multimodal imaging and larger plate formats may broaden applications in bioprocessing and formulation screening.

Conclusion

Aura particle analysis combined with Particle Vue Software offers a comprehensive solution for visible and subvisible particle characterization in complex biological samples. The integrated imaging modalities deliver precise sizing morphological assessment and compositional identification ensuring regulatory compliance and product safety.

References

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5. Wickson B Particulate Matter USP Requirements and Particle Identification PDA Presentation 2019
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