Vesicles usually contains a very small amount of DNA, the most of it is fragmented and single stranded, and the quantity is not enough for an agarose gel analysis. DNA can be quantify by nanodrop analysis and by qPCR.
EXO-DNA Extraction Kits allows the isolation of circulating+extracellular vesicle (EV)-associated DNA and in EVs is contained genomic DNA. It is also possible the presence of some mitochondrial DNA in EVs, but the evidences about this issue are not still very clear. If you want to limit the analysis only to the DNA contained in EVs, it is sufficient to make a DNase treatment after the precipitation of vesicles+circulating DNA, before to add the lysis buffer. Rather, vesicles protect the DNA from the DNase treatment, which eliminates only the circulating DNA fraction.
Yes, there is a possibility of RNA contamination, since the vesicles contain RNA, in particular miRNAs. Percentage of ribosomal RNA is very small in vesicles. Presence of RNA does not cause problems since it is very quickly degraded. It is possible to make an optional treatment with RNase to eliminate the possible contaminations.
No, the ExoDNA™ Extraction Kits does not adopt any RNase treatment, but it is possible to do the RNase treatment once the DNA is eluted.
Lyophilized standards are currently used as a positive control in RNA and DNA kit, so it is possible to use them for isolation of nucleic acids, although each lot has characterized for protein content and particle number (NTA). In addition, many customers are using as mutation control in spike-in experiments.