Exosome Overview

What Are Exosomes?

Exosomes are membranous vesicles approximately 30–150 nm in diameter that are released into the extracellular space through the fusion of multivesicular bodies (MVBs) with the plasma membrane.

According to the prevailing scientific consensus, exosome biogenesis involves the inward budding of the plasma membrane to form early endosomes, which then mature into multivesicular bodies (MVBs) containing intraluminal vesicles. These MVBs subsequently fuse with the plasma membrane, releasing exosomes into the extracellular environment.

Studies have shown that exosomes are secreted by all types of mammalian cells under culture conditions.

What Are the Methods for Exosome Isolation?

Ultracentrifugation

A method for obtaining exosomes through centrifugation at 100,000 × g.

Density Gradient Ultracentrifugation

A method for obtaining exosomes using a density gradient medium and centrifugation at 100,000 × g.

Magnetic Bead Capture

Immunomagnetic Bead Method

This method conjugates antibodies (e.g., CD63/CD81/CD9) to magnetic beads, enabling the capture of exosome surface membrane proteins via antigen‑antibody binding.

PS Affinity Magnetic Bead Method

This method conjugates phosphatidylserine (PS) to magnetic beads, enabling the capture of PS on the outer surface of exosomal vesicles through affinity binding.

Ultrafiltration

Polymer-Based Precipitation

Polyethylene glycol (PEG) is a commonly used polymer that binds to hydrophobic proteins and lipid molecules, resulting in co-precipitation.

Column Purification

Microfluidic Chip Technology

What Is the Typical Yield of Exosomes from Common Sample Types?