A novel approach to stabilize fetal cell-free DNA fraction in maternal blood samples for extended period of time

• Published in: PloS one Vol. 13; no. 12; p. e0208508
• Main Authors: Fernando, M Rohan, Jiang, Chao, Krzyzanowski, Gary D, Somer-Shely, Tifany, Ryan, Wayne L
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.12.2018; Public Library of Science (PLoS)
• Subjects: Aldehydes; Biology and Life Sciences; Blood; Blood cells; Blood plasma; Blood Specimen Collection - instrumentation; Blood Specimen Collection - methods; Care and treatment; Cell-Free Nucleic Acids - blood; Cell-Free Nucleic Acids - chemistry; Crosslinking; Deoxyribonucleic acid; DNA; Female; Fetuses; Formaldehyde; Genes; Gynecology; Humans; Manufacturers; Medicine and Health Sciences; Metabolism; Methods; Molecular Diagnostic Techniques; Obstetrics; Physical Sciences; Polymer crosslinking; Polymerase Chain Reaction; Pregnancy; Pregnancy Trimester, First - blood; Pregnancy Trimester, First - genetics; Pregnant women; Promoter Regions, Genetic; Proteins; R&D; Reagents; Research & development; Research and analysis methods; Technology; Tubes; Tumor Suppressor Proteins - genetics; Nebraska; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0208508

This study was undertaken to evaluate a novel method for stabilizing and preserving the original proportion of cell-free fetal DNA (cffDNA) in maternal blood for extended periods of time without using crosslinking agents, such as formaldehyde, which compromise DNA integrity and extraction efficiency. Blood was drawn from pregnant donors into K3EDTA and Blood Exo DNA ProTeck® (ProTeck) tubes. Blood drawn into both tubes were aliquoted and stored at three different temperatures. At indicated times sample aliquots were processed for cell-free DNA (cfDNA) extraction. Plasma cfDNA and cffDNA quantified by droplet digital PCR (ddPCR) assay which amplify RASSF1A gene promoter region. ProTeck reagent is formaldehyde free and inhibits blood cell metabolism in blood samples during storage. Cell-free DNA concentration increased over time in blood plasma stored in K3EDTA tubes at 4, 22 and 30°C. Blood stored in ProTeck tubes, cfDNA concentration was stable at 4, 22 and 30°C for 21, 28 and 7 days, respectively. In K3EDTA tubes cffDNA proportion decreases steadily over time whereas in ProTeck tubes cffDNA proportion remained stable. This novel technology stabilizes cffDNA proportion in maternal blood samples at 4, 22 and 30°C for 21, 28 and 7 days, respectively.