A major challenge preventing transformative gene therapies from reaching patients is the lack of fit-for-purpose potency assays, which are some of the most important assays in an analytical package but are often the most complex and high-risk.

As a platform technology that needs only a single validated antibody and offers rapid 3-hour runtimes, Simple Western™ lowers the custom assay development hurdles of ELISA and accelerates drug development from pre-clinical phases and scaling to GMP. Plus, Simple Western is a multi-attribute method used in gene therapy development, beyond protein expression potency assays, for quantitative CQA monitoring of purity, titer, empty/ full capsid content, and capsid protein ratio. In this Application Note, we demonstrate a Simple Western relative potency assay with parallel line analysis (PLA) for AAV-mediated gene delivery in cultured human cells. Specifically, we demonstrate:

• Relative protein expression potency between AAV serotypes with high specificity and <5% CVs
• Absolute protein expression measurements in AAV-transduced cells using a recombinant standard curve
• Detection of residual intracellular capsid proteins in AAV-transduced cells as an infectivity surrogate