Role of sodium acetate in DNA isolation?

Answer 1

potassium acetate (KAc) is added, which does three things:

a. Circular DNA is allowed to renature. Sheared cellular DNA remains denatured as single stranded DNA (ssDNA).

b. The ssDNA is precipitated, since large ssDNA molecules are insoluble in high salt.

c. Adding sodium acetate to the SDS forms KDS, which is insoluble. This will allow for the easy removal of the SDS from your plasmid DNA.

Answer 2

SDS and the single stranded DNA have hydrophobic interactions, which causes precipitation. However, this requires a neutralization of pH. This is where potassium acetate comes in; potassium acetate is a neutralizing buffer, lowering the pH to the point that SDS can associate with the single stranded DNA. The potassium salt of dodecyl-sulfate is insoluble. So, the potassium cation associates with the extra SDS, precipitating out the SDS as well, reducing the amount of possible contaminants.

Answer 3

better percipitation of protein for better isolation of dna

Answer 4

Salt would attract the phosphate ends of DNA, therefore Kcl pulls away the DNA from other substances present in the sample and protects the DNA from surroundings.

Answer 5

it is used for the removal of protien