Application Notes:

• Directly measures heat change associated with binding

• True in-solution method – no chemical tagging or immobilization of binding components

• Experiments are entirely computer-controlled, including injection parameters and mixing

• Fast and knowledge-rich compared to other analytical methods

Isothermal Titration Calorimetry (ITC) is a thermodynamic technique for monitoring any chemical reaction initiated by the addition of a binding component, and has become the method of choice for characterizing biomolecular interactions. When substances bind, heat is either generated or absorbed. Measurement of this heat allows accurate determination of binding constants (K_B), reaction stoichiometry (n), enthalpy ( H) and entropy ( S), thereby providing a complete thermodynamic profile of the molecular interaction in a single experiment

In ITC, a syringe containing a “ligand” solution is titrated into a cell containing a solution of the “macromolecule” at constant temperature. When ligand is injected into the cell, the two materials interact, and heat is released or absorbed in direct proportion to the amount of binding. As the macromolecule in the cell becomes saturated with ligand, the heat signal diminishes until only background heat of dilution is observed.

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