Problem with extraction of DNA from Trizol

[max_rempel]

I have generated a number of interesting mouse epidermis samples in Trizol. The treatments include the ones which may affect chronic state of the epidermis and therefore are interesting for methylation analysis. I was able to extract and use RNA from these samples. Now I am trying to extract DNA from the rest of each trizol sample.
The first try gave me very poor quality and low yields of DNA.

My QUESTION: has anyone extracted DNA from Trizol samples and what was the protocol?

[danfive]

Originally Posted by max_rempel

I was able to extract and use RNA from these samples. Now I am trying to extract DNA from the rest of each trizol sample.
The first try gave me very poor quality and low yields of DNA. ?

I had the same thing happen, so I abandoned this method. I also noticed that the RNA from Trizol Extraction contains DNA and therefore needs Dnase I treatment prior to downstream applications.

My advice is to talk with Tech support at Invitrogen.

[max_rempel]

I tried another method, it seems to work ok, not sure what is the relatvie yield, but there is at least something.
Remove upper phase. Add 1/3 volume of 70% ethanol.
Load on Qiagen DNAeasy minispin column from Blood and tissue kit.
Continue with washes as described in the kit.
About 50 mg of epidermis gives about 15 mkg of DNA with reasonable , not too clean, quality of DNA by Nanodrop.
I was also given an advice to adjust pH of Trizol phase before extraction. Didn't try yet.