from Trizol to phenol/chloroform for DNA extraction - (Dec/19/2007 )

I want to isolate genome DNA from patient sample (in Trizol, after remove RNA fraction), however it is heavily contaminated with protein and other junk

people suggested that i should try to conducting 1 or 2 phenol/chloroform for extraction the DNA.

How can i do that?? mix the trizol and phenol/chloroform altogether

thank a lot

Hui ling

the standard way of doing this is to first finished the Trizol extraction protocol. Once you have your DNA in TE, add the phenol/chloroform (1/5 to equal volume).

It is often best to increase make up the DNA in a large volume, say 500ul to reduce the amout of DNA lost during the phenol/chloroform extraction, as you will lose some volume when trying to avoid sucking up the gunk that appears on interphase between the phenol/chlorofom and aqeous supernatant.

Shake the tube a little to mix the two. Then centrifuge and remove the supernatant to a new tube. Leaving behind the junk that appears on the interphase.

Repeat until the interphase is clean.