I recently isolated miRNA from human urine using Quigen miRNeasy serum/plasma kit (which works with urine as well) and quantified using NanoDrop. Even from freshly isolated sample, I am getting a horrible 260/280 ratios like 1.5 and 1.6. Concentration is around 8-30 ng/ul
My feeling is that the choice of Nanodrop is not right as miRNAs are only present in lower amounts in urine and these levels may not be detected accurately by NanoDrop. I can not imagine another reason for such a low ratio (I am pretty sure I did the experiment right).
Has anybody here worked with urinary miRNAs? I would like to know how much is the concentration range you are getting after isolation, and how to you quantify/qualify miRNAs?( I guess it would be Bioanalyzer).