Characterization Of AAV-Based Viral Vectors By DynaPro DLS/SLS Instruments

By Xujun Zhang, Ph.D., Wade Wang, Ph.D., and Sophia Kenrick, Ph.D.

Adeno-associated virus (AAV) consists of a non-enveloped protein capsid with diameter ~25 nm, packed with single-stranded DNA. With a history of over fifty years of study, AAV has become one of the most popular and well-characterized gene-delivery vectors for clinical applications.

When developing adeno-associated virus vectors as drug products, multiple quality attributes must be monitored to ensure a safe and efficacious final product. Three such QAs are total AAV particle concentration, aggregate content, and thermal stability.

A variety of analytical tools are used to monitor QAs of AAV vectors, including analytical ultracentrifugation (AUC) and real-time PCR. However, these techniques can be labor-intensive, costly, and destructive to the sample, making them unsuitable for early-stage, high-throughput screening. SEC-MALS is non-destructive, easier and faster than the aforementioned techniques.

SEC-MALS provides detailed analysis, but requires 30 minutes per sample and may not be appropriate for screening of processes and formulations. In contrast, batch light-scattering techniques provide quick, easy, and high-throughput characterization of AAV solutions, albeit with limited resolution and accuracy in comparison. Here, batch static and dynamic light scattering (SLS and DLS) are used to quantify three AAV QAs: aggregate content, thermal stability, and total viral particle concentration.

This application note highlights all three measurements in both the DynaPro Plate Reader and DynaPro NanoStar DLS/SLS instruments.