Creative Proteomics can efficiently separate high-quality exosomes derived from multiple cell types, such as B cells, dendritic cells and tumor cells and almost any biofluid including plasma, urine, serum, CSF, ascites fluid, and saliva, as well as plants.
We uses different exosome isolation methods including differential ultracentrifugation, size-based isolation of exosomes, exosome precipitation, affinity-based capture of exosome, microfluidics-based isolation of exosome according to customer's detailed requirements.
- Differential Ultracentrifugation
- The isolation of exosomes by differential ultracentrifugation usually consists of a series of centrifugation cycles of different centrifugal force and duration to isolate exosomes based on their density and size differences from other components in a sample;
- Before the start of isolation, a cleaning step is usually carried out for human plasma/serum to rid of large bioparticles in a sample and the sample is spiked with protease inhibitors to prevent the degradation of exosomal proteins;
- Finally, the isolated exosomes are once again re-suspended and stored at -80℃ until further analysis.
Fig1. Schematic representation of isolating exosomes by differential ultracentrifugation (Li P.; et.al, 2017)
- Size-based Isolation of Exosomes
- One of the popular size-based exosome isolation techniques is ultrafiltration;
- Based on their size, exosomes can be isolated using membrane filters with defined molecular weight or size exclusion limits. Ultrafiltration is faster than ultracentrifugation and does not require special equipment;
- Another size-based separation technique applied to exosome isolation is size exclusion chromatography (SEC).
Fig2. Schematic illustration of sequential filtration (Li P.; et.al, 2017)
- Exosome Precipitation
- By altering their solubility or dispersibility, exosomes can be settled out of biological fluids;
- The water-excluding polymers such as polyethylene glycol (PEG) can tie up water molecules and force less soluble components out of solution;
- Hence, samples are incubated with a precipitation solution containing PEG, thus the precipitate containing exosomes is isolated by means of either low-speed centrifugation or filtration. This method is easy to use and does not require any specialized equipment.
- Affinity-based Capture of Exosome
- The presence of plenty of proteins and receptors in the membrane of exosomes offers an excellent opportunity to develop highly specific techniques for the isolation of exosomes.
- Exosome biomarkers for immunoisolation are membrane-bound, lacking soluble counterparts, and solely expressed or highly concentrated on the surface of exosomes from specific biological sources.
Creative Proteomics promises to provide high-quality and low-cost exosomes for global clients. We also believe that our service will make your project achieve twice the result with half the effort. If you have any demands in exosome isolation, please don't hesitate to contact us for more information.