Novel PPT+SEC Workflow for High-Sensitivity Extracellular Vesicle Proteomics from Cell Media

Area of Science:

• Biochemistry
• Cell Biology
• Proteomics

Background:

• Extracellular vesicles (EVs) isolation using size exclusion chromatography (SEC) typically requires a concentration step.
• This concentration step can lead to significant loss of valuable EV material.
• Current methods limit the efficiency of EV proteomics analysis.

Purpose of the Study:

• To develop a novel EV isolation workflow compatible with direct proteomics analysis.
• To minimize EV loss during sample preparation.
• To enhance the sensitivity and scope of EV proteomics.

Main Methods:

• Development of a low-volume EV isolation technique using size exclusion chromatography (SEC).
• Characterization of isolated small EVs via transmission electron microscopy, Western blot, and nanoparticle tracking analysis.
• Proteomics analysis of isolated EVs and benchmarking against an automated UHPLC-SEC platform.

Main Results:

• The novel workflow isolates EVs in 80 microL, eliminating the need for concentration.
• Identified more proteins and EV markers compared to UHPLC-SEC, including 96% of top exosomal proteins from ExoCarta.
• Demonstrated higher sensitivity for pancreatic cancer EV markers in pancreatic cancer cell lines.

Conclusions:

• The developed EV isolation method is efficient and preserves EV integrity for proteomics.
• This approach significantly enhances the identification of EV proteins and biomarkers.
• The workflow shows promise for sensitive detection of cancer-specific EV markers.