Ann Lab Med 2020; 40(3): 253-258
Isolation of Small Extracellular Vesicles From Human Serum Using a Combination of Ultracentrifugation With Polymer-Based Precipitation
Kyung Ju Ryu, Ph.D.1,2, Ji Young Lee, B.S.2, Chaehwa Park, Ph.D.1,2, Duck Cho, M.D., Ph.D.3, and Seok Jin Kim, M.D., Ph.D.1,4
1Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, Korea; 2Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Korea; 3Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; 4Division of Hematology and Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
Corresponding author: Seok Jin Kim, M.D., Ph.D.
Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Korea
Tel: +82 2-3410-1766 Fax: +82 2-3410-1754 E-mail:
Received: May 31, 2019; Revised: September 25, 2019; Accepted: November 14, 2019; Published online: May 1, 2020.
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Methods for reproducibly isolating and enriching small extracellular vesicles (EVs) from blood are essential for clinical utilization of small EVs in cancer patients. We combined ultracentrifugation (UC) with polymer-based precipitation (ExoQuick [EQ] or Total Exosome Isolation [TEI] kit) to isolate small EVs (diameter, 30–150 nm) from the serum of breast cancer patients. We compared the performance of four cycles of UC (UC4x) with that of two cycles of UC followed by enrichment using the EQ (UC2x→EQ) or TEI (UC2x→TEI) kits. The mean concentration of small EVs isolated from 1 mL of serum using UC2x→EQ (139.0±29.1 µg) and UC2x→TEI (140.4±5.0 µg) did not differ from that obtained using UC4x (141.8±26.9 µg). The mean number of EV particles obtained using UC4x was 29.2± 9.9×109 per mL of serum, whereas UC2x→EQ and UC2x→TEI yielded higher numbers of EVs (50.7±17.0×109 and 59.3±20.6×109, respectively). Concentrations of EV microRNAs, including miR-21 and miR-155, did not differ between the three methods. In conclusion, performing UC prior to the use of polymer-based precipitation kits could be feasible for isolating small EVs from human serum in large sample-based translational researches.
Keywords: Extracellular vesicle, Precipitation, Ultracentrifugation, Isolation, Performance

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