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?

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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.

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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.

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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

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