Exosomes are membrane-encapsulated particles typically ranging from 20 to 120 nm in size and contain multiple macromolecules, including proteins, mRNA and miRNA. They have also recently been reported to contain DNA. A number of surface proteins are found exclusively in exosomes.
According to this hypothesis, cells secrete exosomes that are loaded with distinct sets of miRNAs. Exosomes can travel through the bloodstream and fuse with target cells, thereby delivering their miRNA load. Stoorvogel et al. provides proof of principle that, after being transferred by exosomes, miRNAs can repress mRNAs in target cells. Figure adapted from Stoorvogel et al. 2012, Blood 119 (3): 646.
NanoSight measurements of pelleted exosomes from serum and discarded supernatant demonstrates a very high recovery of the exosomes.
NanoSight measurements of pelleted exosomes from cell-conditioned media and discarded supernatant demonstrates a very high recovery of the exosomes
NanoSight measurements of pelleted exosomes from urine and discarded supernatant demonstrates a very high recovery of the exosomes.
Using an exosome isolation kit results in increased call rate from depleted samples and allows greater sample starting volumes. For direct RNA extraction, 200 µl of urine from a healthy individual was used as the starting material for RNA purification. In comparison, greater miRNA qPCR call rates were observed when increasing volumes of urine was subjected to exosome enrichment using the miRCURY Exosome Kit – Cell/Urine/CSF, prior to RNA extraction.