["Tie" calorimetry: theory and experiment].

The results of theoretical and experimental investigations of the interaction of ligands to DNA permit to suggest the method of "tie" calorimetry by means of which the thermodynamic parameters of the cooperative transitions of DNA such as helix-coil, B-A and B-Z transitions were obtained. The prominence of the method is that the experimental samples contain such concentration of DNA that intermolecular interaction may be neglected. Moreover the smaller is the magnitude of the measured parameter the greater is the accuracy of the experimentally obtained data.