Hi, I'm trying to collect exosomes from human plasma. Has anyone used ExoQuick from System Biosciences? I'm trying it out and it seems to work, but I'm still skeptical about what I'm getting from the serum. I'm curious to know if it just precipitate exosomes or does it include microparticles
Don't you have the datasheet?
Look for the exosome markers you will know
http://www3.interscience.wiley.com/journal/122616918/abstract?CRETRY=1&SRETRY=0
Hi Paul,
I have recently started researching exosomes and as far as I can see when comparing methods, you cannot achieve 100% isolation.
Precipitation tends to also precipitated small Micro Vesicles as the sizes overlap. Also other particles such as high density lipoproteins (HDLs). Ultra-centrifugation isolates anything of similar buoyant density (HDLs, MVs, protein aggregates etc.). Size exclusion (filtration/chromatography) can skew results by selecting smaller exosomes as larger bodies can be deformed/disrupted by the process and again doesn't remove smaller MVs. Immuno-affinity isolation seems to be gaining favour among exosome researchers, but as yet no marker has been shown to be expressed solely on exosomes, also protein presentation on exosomes has been shown to differ under different conditions, and therefore selecting for one specific surface marker may provide only a sub-population of exosomes, again skewin results. Combining several markers may overcome this but becomes costly and is still not definitive.
Different papers praise each different method above others and preference seem to depend on what the downstream analysis is.
Although polymeric precipitation (ExoQuick) seems somewhat ignorant of the complexities of exosome isolation, it is commonly regarded as the easiest method and obtains results comparable to, and many times better than, ultra-centrifugation.
Personally I don't like to consider any of these techniques as isolation per se but tend to term it enrichment.
I hope this helps.
try the Total exosome isolation reagents - 5 options optimized for misc body fluids and CM. work well. keep in mind though- plasma is the most challenging sample type for exosome research, due to large number of contaminants of all kinds, and viscosity
- Badges
- Science topic
- Similar topics
- Cell Biology
- Methods