Introduction Nucleic acids are common targets for antiviral, anticancer, and antibiotic drugs. DNA-binding drugs are designed to modulate gene activity, and RNA-binding drugs inhibit protein translation. In order to optimize the efficacy of drugs, as well as discover new drugs, it is important to fully characterize the drug-nucleic acid interaction, including sequence recognition, structural details and the thermodynamics of binding. Microcalorimetry is a tool used to determine the thermodynamics of intermolecular binding. Both Isothermal Titration Calorimetry (ITC) and Differential Scanning Calorimetry (DSC) are used to elucidate thermodynamic details of nucleic acid-drug interactions. Thermodynamics, when used in conjunction with structure, sequence, and computational methods, can be used to optimize drugs to bind specific sequences and/or structures of nucleic acid targets. This application note will review the use of calorimetry to study the thermodynamics of drug-nucleic acid binding. For more information, refer to cited references. Several excellent review articles are also available on this topic (References 1-5). 等溫滴定微量熱儀(生物大分子相互作用儀) ITC ,MicroCal