Results show that divalent cations create shrinkage of DNA, but adding three-valent cations to a DNA solution containing two-valent cations inhibits this shrinkage. S. Nakano and N. Sugimoto presented a review 13 related to the structural stability of DNA and RNA in the presence of organic solvents. The authors discussed some possible mechanisms of the influence of organic solvents on nucleic acid interactions. Among these mechanisms are the influence of the osmotic pressure and effect of the dielectric constant on specific interactions with nucleic acid strands.