Figure 3: Analysis of the exosomal miRNA levels in HeLa cell culture media (a) and serum preparations (b) by quantitative RT-PCR. RNA was isolated using the Total exosome RNA and protein isolation kit from exosomes extracted using the Total exosome isolation reagents and the ultracentrifugation protocols. Levels of five microRNAs (miR16, miR24, miR26a, miR451, and let7e) were quantified by qRT-PCR using TaqMan assays and reagents.