Thermodynamic characterization of the 9-aminoacridme intercalated into DNA

Abstract The interaction of DNA with 9-aminoacridine was studied by means of calorimetric and spectral measurements, and the thermodynamic quantities for 9-aminoacridine intercalated into DNA were determined. Changes in free energy Δ G , enthalpy Δ H , and entropy Δ S accompanying the intercalation process were estimated to be about −36kJ mol −1 , −22kJ mol −1 and 47 J K −1 mol −1 respectively, suggesting that the interaction between DNA and 9-aminoacridine appears to form a stable complex from the viewpoint of free energy and that this complex formation is governed by both enthalpy and entropy.