Trizol RNA/DNA extraction
Posted 29 June 2009 - 07:06 PM
1. The manual says it is important to completely remove the aqueous phase (which was used for RNA isolation) before you start. In doing so, I think I had to remove almost all interphase (insoluble) material. I am using very small amount of tissue so there wasn't much visible interphase in the first place.
2. The manual says to centrifuge at "no more than 2,000 xg". I thought it was a rather slow spin for precipitating nucleic acids. I even asked Invitrogen technical support and they said it was not a typo. Is this (slow spin) what you do? Does it work for you?
Posted 30 June 2009 - 06:09 AM
this spin is not to pellet the nucleic acid, it is to separate the aqueous from the organic phase.
genius does what it must
i do what i get paid to do
Posted 30 June 2009 - 10:06 AM
No no you don't understand. This is AFTER the separation of the aqueous and organic phases. You remove the aqueous phase which contains RNA, then you add 100% ethanol to the organic phase and spin at 2000 g, which is supposed to pellet DNA.
Posted 01 July 2009 - 04:57 AM
I used an Ambion kit and a Qiagen kit for extracting DNA and RNA from one FFPE tissue sample but these kits use first phenol/chloroform then silica columns for the isolation. They work quit good I must say.