Webinar | Tuesday, June 12, 2018 | ccfDNA In the Lab: Optimizing Purification for Sequencing
ccfDNA Webinar Series: The Basics and Beyond
Circulating cell-free DNA (ccfDNA) can be used to monitor tumor burden and monitor disease progress.
In this part 3 of 3 ccfDNA webinars, Dr. Gulley discusses variables important to isolating high-quality ccfDNA from plasma samples including anticoagulant, plasma volume and storage length and conditions.
Review Part 1 & 2
Circulating cell-free DNA assays serve to monitor tumor burden and to track clonal evolution, including emerging drug resistance clones. Among the pre-analytic variables important for assuring high quality sequencing results on plasma DNA are choice of anticoagulant, input plasma volume, extraction chemistry, and the duration and storage conditions of blood before blood is processed to separate plasma. Interfering substances or processes may include hemolysis, leukocyte lysis, and nucleases. Assay validation resources can help in assay design and experimental design to optimize sensitivity, specificity, linearity and reproducibility of sequencing results. Controls, calibrators, and quality checks are valuable tools to demonstrate assays perform as expected. The adverse impact of tumor heterogeneity on tissue-based genomic profiles may be overcome, in part, by testing plasma that may yield a more global or systemic portrait of tumor clones and emerging subclones. Monitoring patients in serial plasma tests performed over time may be more informative than test results at a single timepoint. Ongoing research continues to reveal the utility of plasma DNA as a tool to enhance early diagnosis, tumor classification, and patient response to therapeutic interventions.