Current production processes for gene therapies based on adenoassociated virus (AAV) vectors generate many empty capsids. That problem complicates vector purification and diminishes product safety and quality. In a June 2022 webinar, Gareth Rogers (product manager at Refeyn Ltd.) observed that developers could benefit significantly from analytical instruments that assess empty-to-full (E:F) capsid ratios rapidly. He explained how the SamuxMP mass photometry system (Photo 1) could address such needs. Kirsty McManus (senior scientist in AAV characterization at Pharmaron Gene Therapy)…