Optimized exosome isolation protocol for cell culture supernatant and human plasma

Area of Science:

• Biotechnology and Biomedical Research
• Extracellular Vesicle Biology

Background:

• Extracellular vesicles, particularly exosomes, are vital biomarkers for disease diagnosis and prognosis.
• Current methods for isolating exosomes from cell culture and biological fluids often lack efficiency, yield, and purity.

Purpose of the Study:

• To comprehensively characterize and compare various exosome isolation protocols.
• To identify the most efficient, high-yield, and pure exosome isolation methods for cell culture supernatant and plasma.

Main Methods:

• Comparative analysis of four exosome isolation techniques, including ultracentrifugation, ultrafiltration (centrifuge-based and pressure-driven), precipitation, and size exclusion.
• Utilized tunable resistive pulse sensing and protein analysis for efficacy and purity assessment.
• Tested protocols on Non-Small-Cell Lung Cancer (NSCLC) cell line conditioned media and plasma samples.

Main Results:

• Ultrafiltration devices increased vesicle isolation yield compared to ultracentrifugation.
• Centrifuge-based concentrating methods proved more effective than pressure-driven devices for rapid exosome isolation.
• Precipitation protocols yielded the least pure exosome preparations; size exclusion isolation was comparable to density gradient purification.

Conclusions:

• Identified shortcomings in common extracellular vesicle isolation methods.
• Proposed a standardized, effective, and reproducible method for exosome isolation from diverse starting materials.
• The findings will advance extracellular vesicle research and biomarker discovery.