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DNA Quantification - Problems with DNA Quantification (May/10/2011 )

Hello,

I had a question about the quantification of DNA using the Nanodrop,

I amplified my DNA using normal PCR amplification i purified it with a Qiaquick PCR purification kit and then i measured my samples using the nanodrop, i had the following results:

Concentration (ng/ul) = 18,0
260/280 nm = 1,78
260/230 nm = 2,88!! <- This value concerns me

Does anyone of you have an idea what this high value means, i have looked up some forums and they said it was because the concentration of the DNA was too low but i don't think that this is the problem.

Fact about the DNA molecule, the 5' strand of the DNA molecule has a NH2-C6 group attached to it, could it possibly be some kind of absorbance either from the NH2 or the C6 chain?

Can anyone help me?

-Axelkef-

well the peptide bond does absorb at 230 nm... which is CO-NH so may be even NH2 does.. not sure though!!!!

-Prep!-

I think you want to look at the full spectrum to tell what is going on. It's possible that residual PB or QG buffer contributes to these results. Good luck!
http://www.bioprotocols.info/index.php

-chromatin-