Yakovchuk et al., and Privalov 49 studied the role of base-stacking and base-pairing contribution to the thermal stability DNA using calorimetry (spectrophotometer) and gel electrophoresis. Discussing the role of hydrogen bonding between conjugate base pairs, authors concluded that the formation of hydrogen bonds is an entropy-driven, non-enthalpic process. The disruption of the Van der Waals contacts between base pairs explained large enthalpy values during DNA melting. The authors explained it by a disruption of apolar contacts between bases. This means that a significant part of the DNA denaturation/renaturation's enthalpy is supposed to be allocated to dispersion forces.