Library preparation and analysis of the raw sequencing data. (A) PAGE analysis of the sequencing libraries prepared using three different kits. 20-bp DNA ladders are shown on the left of each panel while the prepared libraries are shown on the right. The anticipated RNA sequencing constructs ranging from 140–160 bp are highlighted within brackets. The DNA bands (~125 bp) are the adaptor dimers. (B) Percentage of mappable RNAs in the raw sequencing reads. (C) Abundance of the selected miRNAs and β-actin in plasma exosomal RNA and HEK293 cellular RNA. Gene and miRNA abundance was determined by the threshold cycle (Ct), where Ct values >30 are defined as rare. (D) Percentage of each miRNA in the repertoire of total miRNA reads.