Small RNA extractions from plasma

[blanco]

Hi all who have some experience/knowledge in working with RNA from plasma.

I just did some extractions and was deterred when I ran the RNA Nano on the bioanalyzer and found no trace of RNA.
I then ran the samples on the 'small RNA' bioanalyzer chip and this time we were able to pick up some RNA.

Attached below is one of our 'good' results.



So, I have a couple of questions:
Is this trace what one would expect from plasma RNA?
And, is this sufficient amount of RNA to construct a 'small RNA' library?

Any kind of help or comments would be appreciated.
Many thanks,
blanco