making 25:24:1 phenol/chloroform/iaa - question (Dec/10/2008 )
I have a bottle with 24:1 chloroform/isoamyl. I want to add in phenol so that in the end I have a working stock 25:24:1 phenol/chloroform/iaa. how do I do this?
I assume this is for cleaning up/extracting DNA? I add 1/2 volume phenol and 1/2 volume sevag (24:1 chloroform/isoamyl) to the sample. So if you have 500ul, add 250ul each of the phenol and sevag.
Don't forget that you need to add water saturated phenol of the appropriate pH for DNA or RNA depending on what you are trying to extract.
Nelsens is right,
just for you to understand the strategy :
you need 25 volume of phenol, 24 volume of chloroform, 1 volume of isoamyl
if you take x mL of chloroform/isoamyl, you have already 24 vol of chlorof and 1 vol of iaa, which is a total of 25 volumes. you need to had 25 volume of chloroform, and 25 volumes correspond to x mL
So you just dilute 1:1 with phenol