Methods for desalting - (Jul/14/2010 )

shouldn't that be glycogen rather than glycerol?

mdfenko on Jul 22 2010, 10:13 PM said:

You are right mdfenko, its glycogen, not glycerol.

I googled this product, concerning humic acid removal. I have never used this kit before. It and other similar products might be of interest to this discussion.

Oops, sorry guys, you're right: glycogen (which I don't have either anyway ).

Perneseblue, funny you mention this kit. I have a student working on bacteria from soil extracts and she has a similar problem as me. The HA inhibit her qPCR. She uses this MP Bio kit to extract and let me tell you that it does not remove all the humic acids. I mean it worked for most of them, but not all.
Some of her samples were really bad and had a A260/A260 lower than 1.
Yesterday she tried 3 clean-up methods on the worse samples. First she extracted some samples in triplicate. Then she either did 2 independent clean up with the MinElute Qiagen kit (do the whole precedure, then all over again with a new column). 2nd method, she did phenol-chloroform followed by MinElute and finally 3rd method: MinElute and ethanol precipitation. They all gave similar results. Tiny bit better but the A260/A280 was 1.2 for all samples.
When she did the ethanol precipitaion, she could see a yellow pellet . So HA does indeed precipitate with the DNA, and it is water soluble so can't be extracted with phenol-chloro-isoamyl and the cherry on the pie, HA bind to silica.
Gosh, are they annoying