Elucidating Methods for Isolation and Quantification of Exosomes: A Review

Abstract

Exosomes are the smallest extracellular vesicles present in most of the biological fluids. They are found to play an important role in cell signaling, immune response, tumor metastasis, etc. Studies have shown that these vesicles also have diagnostic and therapeutic roles for which their accurate detection and quantification is essential. Due to the complexity in size and structure of exosomes, even the gold standard methods face challenges. This comprehensive review discusses the various standard methods such as ultracentrifugation, ultrafiltration, size-exclusion chromatography, precipitation, immunoaffinity, and microfluidic technologies for the isolation of exosomes. The principle of isolation of each method is described, as well as their specific advantages and disadvantages. Quantification of exosomes by nanoparticle tracking analysis, flow cytometry, tunable resistive pulse sensing, electron microscopy, dynamic light scattering, and microfluidic devices are also described, along with the applications of exosomes in various biomedical domains.

Extracellular Vesicles and Pancreatic Cancer: Insights on the Roles of miRNA, lncRNA, and Protein Cargos in Cancer Progression

“…Due to the small size, isolation of exosomal pure samples and their quantification is the major hindrance EV research. Today, ultracentrifugation, ultrafiltration, size exclusion chromatography, precipitation, immunoaffinity-based capture are the current methods employed to isolate EV fraction from biological fluids and cellular medium [153]. Isolation easier and faster with larger and purified yields of EVs has been obtained thanks to the expeditious development of these methods, albeit there are many disadvantages for each of them.…”

Perspectives of Microscopy Methods for Morphology Characterisation of Extracellular Vesicles from Human Biofluids

“…EVs serve as biomarkers to define tumours, they have pro-metastatic potential [16]. However, not all cancer cells might be using EVs to grow and metastasise, and thus not all tumours will reveal their presence by increased number of tumour-specific EVs since recent and more sophisticated methods for EV quantification, including flow cytometry and luciferase-based in vitro assays, show that certain cancer cells release lower amounts of exosomes [23][24][25]. As sources of non-invasive diagnostic biomarkers, EVs could help clinicians utilise mental health biomarkers and determine candidates for treatment strategies [26].…”

Urinary Extracellular Vesicles: Uncovering the Basis of the Pathological Processes in Kidney-Related Diseases

“…Like differential ultracentrifugation, this procedure is time-consuming. Additionally, it employs special requirements, and the extreme g-forces used for EV purification may lead to their disruption and loss of their biological activity [ 56 ].…”