Droplet digital PCR ( ddPCR ) : A third generation of quantitative PCR, water and oil emulsions is used to segment the samples and create droplets to identify and quantify the genetic material in the sample. It is a new PCR technique that directly quantifies DNA copies with an unparalleled degree of precision and without the need for a standard curve or for a high degree of amplification efficiency; all properties that lend themselves to the accurate quantification of both single-stranded and self-complementary AAV genomes. The advantage of ddPCR for the nucleic acid quantification includes: Unparalleled precision: the massive sample partitioning afforded by ddPCR enables small fold decrease in target DNA sequences between samples to be reliably measured. Increased signal-to-noise: enrich for rare targets by reducing competition that comes from high-copy templates. Removal of PCR efficiency bias: error rates are reduced by removing the amp...