It is expected that liquid biopsies with detection and measurement of circulating tumor DNA (ctDNA) in cancer patients will be in clinical routine use in a near future. Use of tumor informed dPCR may be a fast, precise, and highly sensitive method to achieve this. However, there is a need for optimization and standardization of all the steps from sampling to report as well as in cooperation and use of proper QC controls.
This webinar focuses on optimization of the analytical steps including sampling, plasma isolation and purification (yield, degree of single stranded DNA, Proteinase K carryover and elution volume). Setup of ctDNA dPCR with dPCR assay controls, number of replicates and sample QC controls are discussed, including use of spike-in, measurement of contaminating lymphocyte DNA and DNA fragmentation. Strategies to select the optimal dPCR assay, identify germlines mutations, CHIPs and patients that are ctDNA non-shedders are also presented. Finally, different ways to report ctDNA graphically are shown with pros and cons discussed.