Characterization and quantification of adeno-associated virus capsid-loading states by multi-wavelength analytical ultracentrifugation with UltraScan.

We present multi-wavelength (MW) analytical ultracentrifugation (AUC) methods offering superior accuracy for adeno-associated virus characterization and quantification. Experimental design guidelines are presented for MW sedimentation velocity and analytical buoyant density equilibrium AUC. Our results were compared with dual-wavelength AUC, transmission electron microscopy and mass photometry. In contrast to dual-wavelength AUC, MW-AUC correctly quantifies adeno-associated virus capsid ratios and identifies contaminants. In contrast to transmission electron microscopy, partially filled capsids can also be detected and quantified. In contrast to mass photometry, first-principle results are obtained. Our study demonstrates the improved information provided by MW-AUC, highlighting the utility of several recently integrated UltraScan programs, and reinforces AUC as the gold-standard analysis for viral vectors.