Abstract 5683: Evaluation of the utilization of blood collection tubes for cell-free DNA research

Many studies have been conducted investigating cell-free DNA (cfDNA) for disease diagnosis. To prevent cellular DNA release into the plasma, plasma separation within 2 hours of blood collection is required, when utilizing the most commonly used type of tube (BD Vacutainer ® CPT TM ; CPT). These temporal restrictions render operations requiring plasma separation a laborious task. It has been demonstrated that Cell-Free DNA BCT ® tubes (Streck Inc; BCTs) prevented nucleated cell disruption. The use of BCTs may enable us to separate plasma without temporal restrictions. The aim of this study was to evaluate changes in DNA levels in plasma after preservation using two types of collection tubes. Samples were drawn from 7 healthy donors into CPTs and BCTs, and stored at room temperature. Plasma was separated immediately (d0), and on days 3, 6, 9, 12, and 14 after blood collection. The concentrations of DNA in the extracted plasma samples were measured. Blood stored in CPTs showed increases in plasma DNA concentrations over time. The mean DNA concentrations at each time-point were 0.39 (d0), 2.96 (d3), 40.4 (d6), 84.9 (d9), 91.4 (d12), and 94.9 ng/μl (d14). However, plasma DNA levels remained stable in BCTs from 6 days. There were significant differences between the DNA concentrations in BCTs on d0 (0.74 [0.43-1.44] ng/µl) and d14 (1.78 [0.63-4.20] ng/µl) (p = 0.0378). Although significant differences were only observed between d0 and d14 in BCTs, the amount of plasma DNA gradually increased after d6. Furthermore, obvious color changes in the plasma were observed, and the boundary between plasma and PBMCs became unclear over time. These results indicate that BCTs may yield stable cfDNA samples for up to 6 days after blood collection. BCTs may be a novel collection tube for cfDNA research, including liquid biopsies in cancer patients. Citation Format: Fumitaka Endo, Takeshi Iwaya, Takehiro Chiba, Mizunori Yaegashi, Kei Sato, Kohei Kume, Atsuhiro Arisue, Yutaka Nishinari, Ryoko Kawagishi, Takenori Segawa, Satoshi Nishizuka, Akira Sasaki. Evaluation of the utilization of blood collection tubes for cell-free DNA research [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5683. doi:10.1158/1538-7445.AM2017-5683