Free energy calculation for DNA bases in various solvents using Flory–Huggins theory

The solvation of various DNA bases in water, ethanol and chloroform has been explored using the modified Flory–Huggins theory employing Monte Carlo simulation techniques. The extent of solvation has been obtained by computing free energy and entropy of mixing. The calculated thermodynamic properties, free energies, enthalpy and entropy of the bases in the solvent environment reveals that, bases are not generally soluble in water but are soluble in chloroform. These results are in accordance with the previous finding that the bases tend to aggregate in water medium. The Flory–Huggins theory qualitatively describes DNA–solvent interaction. In addition, the results from the present theory depend on the quality of the force field employed in the calculation.