I precipitated one of my exosome samples using the ethanol-sodium acetate process since my concentration of total RNA was pretty low. Initially, when I checked my RNA content in my exosome sample using High Sensitivity Fragment Analyzer, I had no ribosomal RNA content (which is expected for exosomes), but when I precipitated the same sample and performed a fragment analyzer check, it appears like there is a huge peak of 28s/18s. Can someone tell what the reason for this could be? Any suggestions would be very helpful.

Thanks,