What will happen to DNA if salt is added to it?
Increase melting point (Tm)
Decrease Tm
Not affect Tm
Melting lead to denaturation of DNA
This makes the DNA less hydrophilic (less soluble in water). Ethanol has a lower dielectric constant than water so it&;s used to promote ionic bonds between the Na+ (from the salt) and the PO3- (from the DNA backbone) causing the DNA to precipitate.
Metabolism of nucleic acids