Control Materials and Digital PCR Methods for Evaluation of Circulating Cell-Free DNA Extractions from Plasma.

Cell-free DNA is an accessible source of genetic material found naturally in plasma that could be used in many diagnostic applications. Translation of cfDNA analysis methods from research laboratories into the clinic would benefit from controls for monitoring the efficiency of patient sample purification and for quality control of the whole workflow from extraction through to analysis. Here we describe two types of control materials that can be "spiked" into plasma samples to monitor and evaluate different aspects of the workflow. The first control material is an internal control that enables evaluation of extraction efficiency, fragment size bias, and sample inhibition. The second control material serves as a parallel quality control material for measurement of specific genetic targets such as tumor mutations.