Measuring Adeno-Associated Virus (AAV) Vector Genome Titer Using Droplet Digital PCR Protocol

Accurate and reproducible dosing is essential for both preclinical and clinical success in cell and gene therapy, making the exact viral titration of vector genome copies a critical measurement. This process is equally important for achieving optimal transduction efficiency and the resulting downstream potency of cell therapies.

Droplet Digital PCR (ddPCR) offers a precise way to quantify DNA copies directly, eliminating the need for a standard curve. When measuring adeno-associated virus (AAV) vector genome titer, ddPCR provides superior consistency across all manufacturing stages, with a coefficient of variation of less than 10%—a significant improvement over quantitative PCR (qPCR) for both in-process and purified samples.

This application note provides an optimized, step-by-step methodology to measure AAV vector genome titer. It includes reagent preparation, pre-PCR steps like DNase digestion and capsid lysis, and the full ddPCR workflow, culminating in data analysis and viral titer calculation. Review the full application note to begin validating your AAV vector genome titer assay.