Deep dive on the proteome of salivary extracellular vesicles: comparison between ultracentrifugation and polymer-based precipitation isolation

Meng Li, Doudou Lou, Joyce Chen, Keqing Shi, Yong Wang, Qingfu Zhu, Fei Liu, Yating Zhang

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Salivary extracellular vesicles (EVs), as novel functional carriers and potential biomarkers, are usually obtained by ultracentrifugation (UC) and polyethylene glycol (PEG)-based precipitation methods. However, salivary EVs obtained by these two methods have not been systematically compared. Here, we perform an in-depth analysis on EVs isolated by these two methods using proteomics. Both methods obtain EVs ranging from 40 to 210 nm, with the PEG method resulting in a wider size distribution. PEG-separated products were irregularly shaped and aggregated, while UC-separated ones were monodispersed and teacup-shaped. Additionally, the expression of EV-specific markers was higher in UC-separated EVs. Using tandem mass spectrometry proteomics, we identified and quantified 1217 kinds of saliva exosomal proteins and 361 kinds of differential proteins, showing that UC can isolate more EV-related proteins. These results offer some guidance for EV separating and provide potential direction for the use of EVs in non-invasive diagnosis.

Original languageEnglish
Pages (from-to)365-375
Number of pages11
JournalAnalytical and Bioanalytical Chemistry
Issue number2
StatePublished - Jan 2021
Externally publishedYes


  • Extracellular vesicles
  • Polymer-based precipitation
  • Proteomics
  • Saliva
  • Ultracentrifugation

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