The importance of exosomes in the pathology of key diseases have made them popular targets in both basic and pharmaceutical research, therefore, isolation of exosome becomes a prerequisite step before furthering their applications. Creative Biostructure provide different techniques to isolate exosomes from various sample matrices.
The Importance of Exosome Isolation and Purification
As we know that exosomes are small endosome derived lipid nanoparticles (50-120 nm in diameter) secreted into extracellular space by most types of cells. Besides lipids, exosomal content also includes genomic DNA, RNA, proteins which is of great importance. There is cumulative evidence has suggested that exosomes have performed may biological functions particularly in cell-cell communication. More importantly, some exosomes associated proteins and microRNAs are closely related with the pathogenesis of most human diseases by serving as invaluable biomarkers for disease diagnosis, prognosis, and therapy. In order to facilitate the understanding of exosomes biological function and therapeutic application, it becomes crucial to specifically isolate exosomes from a wide spectrum of cellular debris and interfering components, then prepare a highly defined population of exosomes in therapeutic scale by appropriate purification skills.
Figure 1. Isolating exosomes from different body fluids by different isolation techniques. (http://www.101bio.com)
Exosome Isolation Techniques
In order to isolate exosomes reliably and efficiently from complex biological matrices like blood, urine, and body fluid, Creative Biostructure has developed five groups of exosome isolation techniques: ultracentrifugation-based techniques, size-based techniques, immunoaffinity capture-based techniques, exosome precipitation, and microfluidics-based techniques. Creative Biostructure provides reliable and reproducible services to isolate exosomes from almost any biofluid in different scales.
Ultracentrifugation-based Isolation Techniques
The isolation of exosomes by ultracentrifugation is based on their density and size differences from other components in a sample. Ultracentrifugation-based exosome isolation is considered as one of the most commonly used techniques for exosome isolation. This approach has been recognized as the one that is easy to use, cost effective and requiring very little technical expertise to operate. However, the ultracentrifugation process is time consuming and may introduce protein and nucleic acid contamination. To compromise its defects, reagent kit could be used to increase isolation efficiency by magnetic beads coupling.
Size-based Isolation Techniques
Size-based exosome isolation techniques is a size dependent method to isolate exosomes by using membrane filters with defined molecular weight or size exclusion limits. Different size-based isolation methods could be applied based on customers’ request. We could provide the following size-based isolation techniques: ultrafiltration, syringe filter-based rapid fractionation, sequential filtration, size exclusion chromatography, flow field-flow fractionation, hydrostatic filtration dialysis.
Immunoaffinity Capture-based Techniques
The most accurate tool for applying for exosome purification is immunoaffinity. Taking advantage of the presence of plenty of proteins and receptors in the membrane of exosomes, immunoaffinity capture-based technique has been developed for the isolation of exosomes by tapping on immunoaffinitive interactions between those proteins (antigens) and their antibodies, and interactions between the receptors and ligands. A microplate-based enzyme-linked immunosorbent assay (ELISA) has been developed for capturing and quantifying exosomes from plasma, serum, and urine. A combination of other isolation techniques with immunoaffinity capture-based technique could maximize its high specificity because exosomes could be further purified by immunoaffinity.
Exosome precipitation from biological fluids could be made by altering their solubility or dispersibility. In general, samples are incubated with a precipitation solution containing PEG which force less soluble components out of solution. The precipitate containing exosomes is isolated by low speed centrifugation or filtration after overnight incubation. This method is easy to use and requires no specialized equipment, also it is scalable for a large amount of samples. Several kinds of precipitation kits are available upon your request. (add link)
Microfluidics-based Isolation Techniques
To further provide customized service to meet our customer needs, Creative Biostructure offers advanced and specialized isolation techniques by tapping on both the physical and biochemical properties of exosomes. In addition to the usual approaches mentioned above, innovative sorting mechanisms such as acoustic, electrophoretic and electromagnetic manipulations can be implemented to broaden our capability on exosome isolation with significant reduction in sample volume, reagent consumption, and isolation time.
Based on the comprehensive techniques in exosome isolation and purification, Creative Biostructure offers top exosome engineering services to satisfy your demands on exosome study. Please contact us for more information.