Scanning electron microscopy (SEM; 20,000x magnification) was performed on a solubilized pellet from ultracentrifugation of pre-filtered (0.8 µm) plasma compared to a non-lysed eluate of an exoEasy column. Both preparations contain vesicle-shaped structures with an expected size range from 50–200 nm (white arrows; scale bar 200 nm). The preparation from ultracentrifugation also includes many smaller, unidentified structures that do not match the expected shape and size of extracellular vesicles.
Bioanalyzer sizing was performed with vesicle-derived RNA purified by two methods. The plasma was pre-filtered (0.8 µm) to exclude larger particles and subjected to either ultracentrifugation, the current gold standard of vesicle isolation, or the exoRNeasy procedure. Both methods purify RNA of similar size and yield.
RNA from pre-filtered plasma was isolated with exoRNeasy and the flow-through of the exoEasy column was used in direct lysis. Shown are raw CT values from RT-qPCR experiments with duplicate replicate isolations and duplicate qPCR reactions.
* Arroyo, J.D. et al. (2011) Argonaute2 complexes carry a population of circulating microRNAs independent of vesicles in human plasma. Proc. Natl. Acad. Sci. USA 108, 5003.
Starting with filtered plasma, the exoRNeasy Serum/Plasma Maxi Kit provides microvesicle isolation in just 20 minutes. A subsequent 35-minute isolation procedure yields total RNA. Just one hour from sample to microvesicle RNA means you can spend less time getting the RNA, and more time deciphering what it means.