Exosome isolation from distinct biofluids using precipitation and column-based approaches

PLoS One. 2018 Jun 11;13(6):e0198820. doi: 10.1371/journal.pone.0198820. eCollection 2018.

Abstract

The potential of exosomes as biomarker resources for diagnostics, prognostics and even for therapeutics is an area of intense research. Despite the various approaches available, there is no consensus with respect to the best methodology for isolating exosomes and to provide substantial yields with reliable quality. Differential centrifugation is the most commonly used method but it is time-consuming and requires large sample volumes, thus alternative methods are urgently needed. In this study two precipitation-based methods and one column-based approach were compared for exosome isolation from distinct biofluids (serum, plasma and cerebrospinal fluid). Exosome characterization included morphological analyses, determination of particle concentration, stability and exosome preparations' purity, using different complementary approaches such as Nanoparticle Tracking Analysis, Electrophoretic Light Scattering, Transmission Electron Microscopy, EXOCET colorimetric assay, protein quantification methods and western blotting. The three commercial kits tested successfully isolated exosomes from the biofluids under study, although ExoS showed the best performance in terms of exosome yield and purity. Data shows that methods other than differential centrifugation can be applied to quickly and efficiently isolate exosomes from reduced biofluid volumes. The possibility to use small volumes is fundamental in the context of translational and clinical research, thus the results here presented contribute significantly in this respect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers / metabolism
  • Body Fluids / metabolism*
  • Colorimetry
  • Exosomes / chemistry
  • Exosomes / metabolism*
  • Humans
  • Microscopy, Electron, Transmission
  • Nanoparticles / chemistry
  • Nanoparticles / metabolism
  • Proteins / analysis
  • Proteomics
  • Ultracentrifugation

Substances

  • Biomarkers
  • Proteins

Grants and funding

This work was funded by PTDC/DTPPIC/5587/2014 and supported by Instituto de Biomedicina (iBiMED)-UID/BIM/04501/2013 and POCI-01-0145-FEDER-007628, the Fundação para a Ciência e Tecnologia (FCT) of the Ministério da Educação e Ciência, COMPETE program, the QREN and the European Union (Fundo Europeu de Desenvolvimento Regional). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.