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Updated: Apr 27, 2026
Protein Digestion, Ultrafiltration, and Size Exclusion Chromatography to Optimize the Isolation of Exosomes from Human Blood Plasma and Serum
Published on: April 13, 2018
Reproducibility and efficiency of serum-derived exosome extraction methods
Josselin Caradec1, Geetanjali Kharmate1, Elham Hosseini-Beheshti1
1Vancouver Prostate Centre, University of British Columbia, Canada; Department of Urologic Sciences, University of British Columbia, Canada; Faculty of Medicine, University of British Columbia, Canada.
ExoQuick™ is a reproducible method for isolating exosomes from human serum, unlike ultracentrifugation. Protein concentration is unreliable for quantifying exosomes due to albumin contamination in ultracentrifuged samples.
Area of Science:
- Biotechnology
- Biochemistry
- Molecular Biology
Background:
- Exosomes are key biomarkers for disease diagnosis and prognosis.
- Current methods for quantifying exosomes in human serum lack standardized protocols for efficiency and reliability.
Purpose of the Study:
- To evaluate the efficiency, reproducibility, and reliability of ultracentrifugation and ExoQuick™ for exosome isolation and quantification from human serum.
- To assess the impact of protein contamination on exosome quantification methods.
Main Methods:
- Exosomes were isolated from human serum using ultracentrifugation and ExoQuick™.
- Quantification involved protein concentration (BCA assay) and nanoparticle tracking (Nanosight™).
- Exosome quality was verified via Western blotting for exosomal markers (CD9, LAMP2) and a negative marker (Grp94).
Main Results:
- ExoQuick™ demonstrated reproducibility and efficiency in exosome quantification via nanoparticle tracking.
- Ultracentrifugation showed correlation with serum volume for protein quantification but was less reproducible.
- Ultracentrifuged exosomes exhibited significant albumin and IgG contamination, compromising protein-based quantification.
Conclusions:
- ExoQuick™ is a superior method for isolating exosomes for quantitative analysis in serum.
- Ultracentrifugation is not recommended for reproducible exosome quantification due to contamination issues.
- Albumin contamination in ultracentrifuged exosomes invalidates protein concentration as a reliable quantification metric.
