Abstract

Considerations and Quality Controls When Analyzing Cell-Free Tumor DNA

Anders Stahlberg, Principal Investigator, University Of Gothenburg

Analysis of circulating cell-free tumor DNA (ctDNA) in liquid biopsies offers new means for early cancer diagnostics, real-time monitoring of treatment efficiency and detection of relapse. Despite its potential use ctDNA remains challenging to detect and to quantify as it represents only a small fraction of all cell-free DNA. We have developed an ultrasensitive sequencing technology, SiMSen-Seq, that allows allele frequencies < 0.1% to be detected. SiMSen-Seq is simple to perform, flexible in multiplexing and requires minimal DNA input. Here, we discuss important considerations for ctDNA detection in plasma, including all experimental steps from sampling to data interpretation. We will also discuss how the use of high fidelity enzymes reduce error rates in barcoded NGS. The use of quality control assays enables the development of robust and standardized workflows that facilitate the implementation of ctDNA analysis into clinical routine.