Immunoaffinity based methods are superior to kits for purification of prostate derived extracellular vesicles from plasma samples

Sabine I. Brett, Fabrice Lucien, Charles Guo, Karla C. Williams, Yohan Kim, Paul N. Durfee, C. J. Brinker, Joseph I. Chin, Jun Yang, Hon S. Leong

Research output: Contribution to journalArticlepeer-review

27 Scopus citations

Abstract

Background: The ability to isolate extracellular vesicles (EVs) such as exosomes or microparticles is an important method that is currently not standardized. While commercially available kits offer purification of EVs from biofluids, such purified EV samples will also contain non-EV entities such as soluble protein and nucleic acids that could confound subsequent experimentation. Ideally, only EVs would be isolated and no soluble protein would be present in the final EV preparation. Methods: We compared commercially available EV isolation kits with immunoaffinity purification techniques and evaluated our final EV preparations using atomic force microscopy (AFM) and nanoscale flow cytometry (NFC). AFM is the only modality capable of detecting distinguishing soluble protein from EVs which is important for downstream proteomics approaches. NFC is the only technique capable of quantitating the proportion of target EVs to non-target EVs in the final EV preparation. Results: To determine enrichment of prostate derived EVs relative to non-target MPs, anti-PSMA (Prostate Specific Membrane Antigen) antibodies were used in NFC. Antibody-based immunoaffinity purification generated the highest quality of prostate derived EV preparations due to the lack of protein and RNA present in the samples. All kits produced poor purity EV preparations that failed to deplete the sample of plasma protein. Conclusions: While attractive due to their ease of use, EV purification kits do not provide substantial improvements in isolation of EVs from biofluids such as plasma. Immunoaffinity approaches are more efficient and economical and will also eliminate a significant portion of plasma proteins which is necessary for downstream approaches.

Original languageEnglish (US)
Pages (from-to)1335-1343
Number of pages9
JournalProstate
Volume77
Issue number13
DOIs
StatePublished - Sep 15 2017

Keywords

  • atomic force microscopy
  • extracellular vesicles
  • nanoscale flow cytometry
  • prostate cancer

ASJC Scopus subject areas

  • Oncology
  • Urology

Fingerprint Dive into the research topics of 'Immunoaffinity based methods are superior to kits for purification of prostate derived extracellular vesicles from plasma samples'. Together they form a unique fingerprint.

Cite this