Comparative study by 454 sequencing of small RNA content of exosome-like vesicles and total cells

Microarray analysis has shown that exosomes contain microRNA. To more carefully define the kinds of small RNA contained in exosomes, and their relative proportions compared to cells, we made libraries for 454 sequencing of RNA obtained from purified exosome-like vesicles and from RNA obtained from the cells from which exosome-like vesicles were purified. We found that exosome-like vesicles contain predominantly mature miRNA, compared to miRNA passenger strands or other pre-miRNA fragments.