Blake Balcomb and Md Abdur Rahim true

Hi Tibutius Thanesh Pramanayagam Jayadas

The expected value for RNA purity is around 2.0-2.2. Generally higher values indicate contamination either from direct nucleotide contamination, however the most common contaminant is usually the reagents used in extraction. If the wash steps were not done adequately then the residual phenols, trizol compounds as well as guanidine compounds are carried through into the final elution. Without seeing the full spectra, I would say you just have a small amount of extraction reagent. Another aspect is the

Blake Balcomb and Md Abdur Rahim true

Thank you all. I'll do the washing step again and try to remove the contaminants and see.

Thank you

The 260/230 ratio indicates chemical contamination. You can try to purify your extracted RNA with the GeneJET RNA Cleanup and Concentration Micro Kit from Thermo. It will help to concentrate the RNA and also clean up the contamination. Hope this helps!

I agree with the others about phenolics. Not so sure about guanadinium or Trizol; I think it's only aromatics that absorb in that region, but I could be wrong.

Another thing to watch out for is whether the concentration is high enough to measure acurately; absorbance values below 0.05 are subject to large errors, and the nanodrop is designed for convenience, not precision.