The cohesion or solubility parameter represents a substance's cohesive energy density or the energy needed to vaporize one mole of a substance and expand the vapor until molecules cannot interact. Cohesion or solubility parameter study and its practical applications in multiple areas of human activity 68 , 69 , 70 has attracted the attention of many scientists in the academy and industry . Several published theoretical articles attempted to extend the predictability of Hansen parameters beyond the solubility of polymers 73 , 74 . We found no attempts in the literature to find the relationship between the experimentally determined cohesion parameters (HSP) and DNA denaturation in different solvent/cosolvent compositions. One of the purposes of the present article is to find such a relationship. According to its definition, the cohesion parameter is part of the enthalpy of solubility processes and is used to find/define the boundary for solute-solvent solubility.