Recombinant Adeno-Associated Viruses (rAAV) are a well-studied class of viral vector that is being investigated intensively in the development of gene therapies. In order to develop efficient rAAV therapies produced through controlled and economical manufacturing processes, multiple challenges remain to be addressed.
rAAVs are typically produced in engineered cell lines in large bioreactors. Once produced inside the cell, the rAAV particles are released by lysis, and then isolated from the bulk harvest through multiple rounds of isolation; for example, via density gradient centrifugation, ion-exchange chromatography, and tangential flow filtration.
Throughout the downstream purification process, multiple assays are performed to determine key analytical attributes for the determination of yield, efficacy, and safety, as well as to enable process understanding and control. These parameters are typically, but not limited to, the following: capsid or particle count, genome count, % genome-containing or % full rAAV particles, serotype characterization, particle size, aggregation level and the presence of unwanted host-cell proteins and nucleotides.
The first three parameters (capsid/particle count, genome count, % full) are commonly measured using two or more of the following assays: qPCR, ELISA, AUC, HPLC-AEX, and/or TEM. Each method has intrinsic strengths and weaknesses, related to the parameter measured, desired throughput, accuracy, and sample volume requirements.
Multi-angle Dynamic Light Scattering (MADLS) is a novel technique capable of simultaneously measuring multiple rAAV parameters, including aggregation, capsid charge, and particle concentration. It is well-suited as a complementary assay that can be utilized in existing analytical workflows to provide rapid, label-free, non-destructive, low volume determination of the total rAAV particle concentration.
In this webinar, Jonathan Mehtala of Malvern Panalytical will discuss the MADLS measurement principle and the application of this novel method to the characterization of rAAV model samples, as well as rAAV therapies in development. The resulting data on the viral concentration and size of rAAV particles will be discussed, along with the effects of sample properties, such as material refractive index and viscosity. Kirsty McManus of Allergan will follow this with real world-examples of multi-serotype rAAV analysis case studies of drug substance and process development samples.
Please join us to learn more about the fast-moving world of gene therapy and the analytical characterization techniques designed to deliver robust, reliable and rapid results.