A novel method for quantitation of AAV genome integrity and residual DNAs using duplex digital PCR

Abstract

Recombinant adeno-associated virus (rAAV) vectors have become a reliable strategy for delivering gene therapies. As rAAV capsid content is known to be heterogeneous, assays for rAAV characterization are critical for assessing the efficacy and safety of drug products. Multiplex droplet digital PCR (ddPCR) has emerged as a popular molecular approach for characterizing capsid content due to its high level of throughput, accuracy, and replicability. Despite growing popularity, tools to accurately analyze multiplexed data are scarce. Here, we introduce a novel model to estimate genome integrity from duplex ddPCR assays. This work demonstrates that use of a Poisson-multinomial mixture distribution significantly improves the accuracy and quantifiable range of duplex ddPCR assays over currently available models.