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Order of salt addition inpurification - (Jul/29/2001 )

Hi- When doing a phenol-chloroform extraction/ethanol precipitation on DNA from a restriction digest, does it matter whether one adds salt (NaOAc) before or after the extraction? For some reason, I added the salt before the phenol-chloroform extraction; normally, I add it after the extraction but before adding ethanol. If this is wrong (because the acetate is soluble in phenol), is there any way of fixing the mistake once ethanol has already been added?



Although the acetate happens to be soluble in phenol I have seen that it doesn't matter .Further I have also added salt after addition of alcohol and has observed it works fine although there was no positive control to compare the effieciency.sankar