In the rapidly developing field of gene therapy, adeno-associated virus (AAV) represents one of the
most prominent and promising platforms for therapeutic application. Different serotypes of AAVs have demonstrated preferences for targeting specifific tissues and represent an auspicious approach for delivering genetic information into patients. A critical quality attribute (CQA) of AVVs is their capsid loading because it influences dose and purity. Capsid loading reflects the effificiency of encapsulation of the genetic material into the viral capsid and is defifined as the ratio of full to empty particles.
Quantifification of capsid loading is an essential aspect of product characterization and can be
determined by different analytical techniques, like AUC, SEC-MALLS, and AEX-FLR. AUC remains
the gold standard, capable of resolving partially fifilled capsids in addition to full and empty capsids.
SEC-MALLS and AEX-FLR are advantageous because they allow for GMP-compliance and higher
This paper highlights the importance of quality control strategies for AAVs with state-of-the-art
analytical capabilities that can reveal signifificant variations of the quality of commercially available AAV
products. For highly parallelized analysis, DLS is a suitable addition to AUC, SEC-MALLS and AEX-FLR
to tackle quality control aspects of AAVs.