Figure 1.

L. donovani exosomes contain RNA cargo. Exosomes were purified from L. donovani axenic amastigote culture supernatant as described in the Methods. RNA was extracted from exosomes or whole cells by phenol-chloroform extraction and then analyzed. A. Agilent Bioanalyzer RNA length profiles of exosome RNA alongside total RNA (~100 ng RNA were loaded for each), B. Gel-like image from Agilent Bioanalyzer measurement, C. Purified exosome RNA (~250 ng/sample) was either left untreated or treated with DNase I, RNase A or KOH followed by radiolabelling with γ³²P dATP and separation on a denaturing 15% polyacrylamide gel, D. RNA inside exosomes is resistant to degradation. Prior to RNA extraction, intact exosomes (purified from 400 mL culture supernatant) were either left untreated, or treated with RNase A or TritonX-100 or both. As a control for RNase A activity, 1 μL of the Agilent pico ladder was treated with the same concentration of RNase A. Samples were then subjected to RNA extraction and run on the Agilent Bioanalyzer. Arrowhead indicates internal 25 nt marker. nt, nucleotides. All images are representative of at least 3 independent experiments.