Microbiology JoVE (Open Access) Citable · DOI

Isolation and Characterization of RNA-Containing Exosomes

Name: Isolation and Characterization of RNA-Containing Exosomes
Uploaded: 2026-06-30
Duration: 9 min 43 s
Description: The field of exosome research is rapidly expanding, with a dramatic increase in publications in recent years. These small vesicles (30-100 nm) of ...

DOI: 10.3791/3037-v

What you'll learn

✓ Isolate and purify exosomes from cell culture media and biological fluids
✓ Characterize exosome size, morphology, and protein composition using multiple techniques
✓ Extract and analyze RNA content from isolated exosomes
✓ Apply electron microscopy, flow cytometry, and Western blot to exosome detection

Protocol

This paper demonstrates methods for the isolation, purification and detection of exosomes, as well as techniques for analysis of their molecular content. These methods are adaptable for exosome isolation from both cell culture media and biological fluids, and can beyond analysis of molecular content also be useful in functional studies.

Difficulty

intermediate

Total time

~4–6 hours per sample batch (isolation through characterization)

Biosafety

BSL-1

Steps

Isolate exosomes from culture media or biological fluids

Perform differential centrifugation and size-exclusion or precipitation-based purification to isolate exosomes from clarified biological samples. Methods are adaptable for both cell culture supernatant and patient-derived fluids.

▶ 01:22

Examine exosome morphology by electron microscopy

Prepare and image exosome samples using transmission electron microscopy to visualize their characteristic cup-shaped morphology and confirm size range (~30–150 nm).

▶ 02:53

Detect and characterize exosomes by flow cytometry

Label exosomes with fluorescent antibodies against surface markers and analyze by flow cytometry to determine particle concentration, size distribution, and protein composition.

▶ 03:23

Analyze exosomal protein markers by Western blot

Lyse isolated exosomes and quantify canonical protein markers (TSG101, CD9, CD63, Alix) by gel electrophoresis and immunodetection to confirm exosome identity.

▶ 04:49

Extract and analyze RNA from isolated exosomes

Isolate total RNA from exosome preparations and characterize via qPCR, RNA-seq, or similar molecular techniques to determine RNA cargo composition and abundance.

▶ 06:08

Interpret integrated exosome analysis results

Review and synthesize data from electron microscopy, flow cytometry, Western blot, and RNA analysis to establish exosome identity, purity, and molecular content for downstream functional studies.

▶ 07:13

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