Madhurima Chatterjee

Thank you anyways.

Article The Exosome Total Isolation Chip

@johnathon thank you! Is there any of those things sold commercially?

You have tangential filtration systems available from Pall (i think the smaller lab-scale device is about 3,000 dollars then you have it for a while, you only need to change the filters), you can contact their services to discuss about the filter sizes or possibly have a demonstration. Actually, the answer to your question depends on what you consider large volumes. If it is litters, lab-scale tangential filtration, diafiltration or ultracentrifugation are good enough. You could even look for affinity chromatography. For higher volumes, you could scale up to large flow filtration/tangential filtration systems, though you might need to setup filter clogging troubles and define the right size of the pores to avoid contaminants plus you might not only isolate exosomes but other extracellular vesicles subtypes that are found conjointly with exosomes in various biological fluids. So if you specifically want exosomes, you might want to consider coupling an extracellular vesicles enrichment process like tangential filtration with a vesicle purification process like velocity/density gradient/affinity/immune purification kits. You can hardly enrich and purify a specific EVs subset from large volumes at the same time.

Hi Grace,

The problems involved in the extraction of exosomes you mentioned may be complicated. Of course, my experiments only involve simple exosome separation techniques based on ultracentrifugation. I know that Creative Biostructure may have related products and services, I feel good, you can try.

https://www.creative-biostructure.com/exosome-isolation-and-purification-650.htm

Good luck!

Our Ultra cent. can only hold 30 cc of material which is way too small if I need 2 Liters from many samples...

Then you should work with filtration but it only concentrates EVs. Then you can use the ultracentrifuge to purify concentrated EVs (in low volume) using gradients or you can work with size exclusion chromatrography. In all cases you will need concentration step before doing a purification.

We use the Millipore Labscale tangential flow filtration system with some pellicon XL ultrafiltration Biomax 500 kDa filters on them. Consider blocking the filters with some protein before you run anything good and doing a pre-filtration step with a 0.4 or 0.2 uM filter. We put through 1-2 L (500 ml at a time with volume reduction steps followed by 3x volume exchange with PBS and a final volume reduction to about 7-15 ml). We used it in a couple of papers already, but we're not particularly novel (@Johnathon Anderson has the same system, probably what @Abderrahim Benmoussa was referring to as well).

PMID: 29323194, PMID: 29076623

Bonus points: it's easier to move into cGMP manufacturing!

Darwin Prockop has used similar volumes with size-exclusion chromatography.

Thank you so much for the informative answer!