Apart from trivial things like faulty and not cleaned nanodrop, high values makes me worry abt contamination. A little extra DNAse treatment may help? These kits use size exclusion filters to increase miRNA yield and there are times when defective filters give low yields but never heard of high yields. If its just three samples, also please try Trizol and compare.

High 260/280 purity ratios are not indicative of an issue. Although purity ratios and spectral profiles are importantindicators of sample quality, the best indicator of DNA or RNAquality is functionality in the downstream application ofinterest.If the purity ratio is significantly higher thanexpected, it is best to review the spectral profile as a primarymeans of troubleshooting.It is important to note that there are occasions when the purityratios are within expected limits, yet there is a problem withthe sample

http://www.nanodrop.com/Library/T042-NanoDrop-Spectrophotometers-Nucleic-Acid-Purity-Ratios.pdf

Hi Sarah,

That is indeed a very high 260/280 ratio.  Perhaps the kit has an absolute requirement for the DNAse treatment so the column can be correctly eluted for RNA.  Often companies make their kit reagents interdependent and absolute requirements so that one has to continually purchase the limiting component(s).  Your 65.3 ng/uL indicates an A260nm NanoDrop reading of about 1.6325 and a 260/280 ratio of 10.08 indicates an A280nm reading of ~0.161954.  Was this the case?

Sarah Bell did you ever discover what caused the high A260/280 ratio? It's happening to me now and can't find an explanation.