1 reply to this topic

[lucilius]

Dear all,

I got a bit confused about the role of sodium acetate in DNA extraction protocols.
I was told it helps to neutralise the DNA charge so that DNA could be precipitated easier with the ethanol added.
However I also saw on some webpages that it also helps precipitng the DNA by binding to proteins (bound to the DNA).

I can understand it helps precipitating the DNA, but if it precipitates with the DNA + proteins , than how do you get rid of those protains after the precipitation?
Because you simple "clean" it with ethanol to remove salts, but you dont remove the proteins , or do you?

[bob1]

The role is to increase the number of ions in solution to a point where the DNA can be precipitated by the addition of an alcohol primarily.  In some extractions such as plasmid preps, it is used to neutralize the alkaline component of the lysis (step 2 NaOH and SDS) and precipitate the proteins and genomic DNA from this step, again through ionic strength.