Accurately Quanitfy Capsid Protein Ratios

By Hüseyin Besir, Ph.D., Rene Wetzel, Ph.D., Dana Holzinger, Ph.D., Caroline Odenwald, Ph.D. and Katja Betts, EMSc, PROGEN, and Rachel Talis, Francisco Ramirez, Charles Haitjema, Ph.D., Kelly Gardner, Ph.D., and Chris Heger, Ph.D., ProteinSimple, a Bio-Techne brand

Adeno-associated viruses (AAV) represent the most commonly used viral vector for the delivery of therapeutic transgenes. However, the gene therapy community is facing major challenges like the high demand for efficient production of high-quality AAV vectors in clinical scale quantities. Robust, quality protein standards and fast, automated highly sensitive analytical instrumentation are needed to address these challenges. Comprehensive monitoring of VP1, VP2, and VP3 protein concentrations and their molar ratios is an effective tool to ensure initial optimization and consistent quality of the final AAV gene therapy products. Here we introduce PROGEN´s recombinant VP standards used with Simple Western™ automated capillary electrophoresis in fit-for-purpose solutions for VP capsid protein ratio and viral protein titer measurements. We further show the establishment of the AAV2 VP protein standards by PROGEN as well as the assay performance data that demonstrates linearity and high sensitivity in an automated workflow optimized for AAV samples.