Shattering Particle Analysis Limitations with Backgrounded Membrane Imaging

Emerging Techniques for Low-Volume and High-Throughput Subvisible Particle Analysis

Particle analysis plays a key role in drug development, yet many of today’s technologies face limitations when detecting subvisible particles, as highlighted in a recent publication.

There are many recognized analytical techniques, such as light obscuration, microscopic particle counting, flow imaging, and Coulter counter, that have been designed for counting and sizing subvisible particles. However, these methods generally fall short when it comes to high-throughput particle screening, a requirement often present during the initial stages of formulation development.

The good news is that we’re witnessing a rapid emergence of new technologies, rooted in novel physical principles for particle detection. These promising developments hold the potential to revolutionize the way we approach the challenges associated with protein therapeutics. One example of these new technologies is Backgrounded Membrane Imaging (BMI) developed by Halo Labs.

High Contrast Particle Imaging for Visible and Subvisible Analysis

Aura® subvisible particle analysis instruments have emerged as an effective solution to address the demand for low-volume and high-throughput quantitative subvisible particle analysis. This instrument employs BMI, a highly sensitive technology rooted in membrane microscopy.

In the BMI method, samples are filtered through a membrane, effectively capturing particles. Microscopic images of the membrane, both before and after sample filtration, are then taken. The images of the particles are subsequently obtained by subtracting the background membrane image from the image of the same membrane with the captured particles.

Thanks to the high refractive index contrast provided by BMI, the sensitivity of the Aura instrument is approximately ten times greater than techniques based on measurements in liquid, such as flow imaging and light obscuration. Aura can accommodate a particle size range of 2 μm to 2 mm. For quantitative results, a sample volume of 25–40 μL is typically required, while a mere 5 μL is sufficient for qualitative rapid screening.

Leveraging novel optics, innovative image processing algorithms, and advanced automation technology, the Aura instrument can screen up to 96 samples in less than two hours. This high-throughput capability enables the inclusion of particle analysis into pre-formulation development where the analysis of tens or even hundreds of samples is often necessary.

Conclusion

The quantification and analysis of the full spectrum of protein aggregates are crucial in understanding, evaluating, and mitigating product changes resulting from interfacial stress. Several emerging methods can be used to gain insight into the nature of aggregates that are formed due to interfacial stresses. One such innovative approach is BMI, which integrates robotics, image processing, optics, and Fluorescence Membrane Microscopy (FMM) to advance and improve the accuracy of particle characterization, making research smarter and safer. Yet is clear that researchers will need to develop comprehensive and multi-faceted strategies for their particle analysis and characterization.