Bioassay Development: Droplet Digital PCR (ddPCR)

Droplet Digital PCR (ddPCR) is a refinement of the well established RTqPCR and qPCR technology for the specific identification and amplification of target gene sequences for quantitation. While qPCR has been the benchmark for evaluation of cDNA and gDNA levels of target genes for decades, it does have some significant liabilities with regards to the potential for artifact when evaluating subtle differences in gene expression (<2-fold). The ddPCR process minimizes this risk by a partitioning of a traditional qPCR reaction into tens of thousands of nano liter droplets, which allows the mathematical determination of the number of target molecules in a given sample based on Poisson Distribution estimation. The increased confidence in ddPCR data has led to applications in Absolute Quantitation without standard, copy number variation (CNV) as well as rare mutation and sequence detection. Additionally, ddPCR is quickly becoming the go-to technology for evaluation of Vector Genome copy number in production of Adeno Associated Virus (AAV) and Lentivirus vectors and therapeutics and nucleic acid residuals in R&D/cGxP manufacturing workflows.