Glycosaminoglycans (GAGs) are large polysaccharides that interact with proteins and lipids through glycosidic bonds, forming the extracellular matrix. GAGs are present in extracellular vesicles (VEs), which are nano-sized structures delimited by a lipid bilayer. Cells release these VEs and their charge is crucial in intercellular communication. ExoGAG is a patented method for the purification of extracellular vesicles, capable of isolating vesicles from liquid biopsy samples. After isolation, proteins or genetic material (DNA, RNA, or microRNA) contained in the VEs can be analyzed using techniques such as qPCR, ddPCR, BEAMing, and sequencing.
Exosomes have great potential as therapeutic or diagnostic tools, but their applications are limited by current extraction methods: low efficiency, slow speed, and high cost. ExoGAG is a simple and rapid method for isolating extracellular vesicles from a small amount of sample. Therefore, ExoGAG is an ideal product for biomarker discovery.
ExoGAG Product Range
Amerigo Scientific offers EXOGAG kits for the isolation of exosomes from different complex biological liquid samples. The ExoGAG precipitation reaction is based on the interaction between the precipitation solution and glycosaminoglycans located on the surface of exosomes. After a simple incubation, exosomes can be isolated through a short centrifugation.
Product Features
Using the EXOGAG kit, exosomes can be isolated from a sample with a minimal amount of co-precipitated material (such as proteins or genetic materials, including DNA, RNA, or microRNA).
- High sensibility and specificity
- Inexpensive
- No specific equipment needed
Exosome Purification Workflow
Figure 1. Workflow of ExoGAG Exosome Purification
Comparison of ExoGAG and Ultracentrifugation Methods
A direct comparative analysis of EV preparations isolated from the same initial cerebrospinal fluid sample using ExoGAG and ultracentrifugation (UC) was conducted. The total protein content was assessed using two different methods, Sypro staining and BCA method. Both methods indicated that the total protein concentration in the samples isolated using ExoGAG was significantly higher than that in the samples isolated using UC. These results were also reflected in the analysis of the particle numbers detected in the isolated EVs by NanoSight tracking analysis (NTA), where the number of particles using ExoGAG was higher than that using UC. The average concentrations of EVs isolated using ExoGAG and UC were 1.05×10⁹ and 6.03×10⁸ particles/mL, respectively. As for the particle size, ExoGAG and UC showed different profiles. With ExoGAG, three different peaks were observed at 65, 135, and 205 nm, while with UC, the majority of the particles had a size of around 115 nm.
Figure 2. Comparative analysis of ExoGAG and UC isolated CSF EVs: protein estimation and NTA
(Int. J. Mol. Sci. 2024, 25(24), 13705)
Through Western blot analysis, it was confirmed that the EV markers CD81 and Alix were present in both cases. The levels of CD81 and Alix proteins obtained using the ExoGAG method were normalized relative to those obtained through the UC method. Compared with the EVs isolated by the UC method, the levels of CD81 in the EVs isolated by ExoGAG were higher, and the level of Alix also showed an increasing trend. The enrichment of CD81 and Alix observed in the ExoGAG isolation can be attributed to the specific precipitation-based mechanism of this method, which may enhance the recovery of vesicles enriched in these markers compared to the UC protocol.
Figure 3. EV enrichment in ExoGAG-isolated versus UC-isolated EVs
(Int. J. Mol. Sci. 2024, 25(24), 13705)
Related Products
Exosome Detection with Flow Cytometry
Exosomes are difficult to identify because of their small size, strong heterogeneity, and low refractive index. The use of flow cytometry not only enables high-throughput analysis of exosomes, but also allows quantification or classification of exosomes based on their antigenic expression.
Common Exosome Isolation Solutions
Amerigo Scientific offers common solutions for exosomes isolation from biological fluids with all the guarantees, such as size exclusion chromatography, polymer precipitation, and immunoaffinity capture-based isolation.
.
