Isothermal Titration Colorimeter

photo of isothermal titration colorimeter

Location: Level 4 South, Room 417

Model: GE Healthcare MicroCal iTC200

Isothermal titration calorimetry (ITC) provides quantitative information on biomolecular interactions via the determination of the thermodynamic parameters of binding.

Example applications include:

  • Characterization of molecular interactions of small molecules, proteins, antibodies, nucleic acids, lipids and other biomolecules
  • Lead optimization
  • Enzyme kinetics
  • Assessment of the effect of molecular structure changes on binding mechanisms
  • Assessment of biological activity

The following information is provided by GE Healthcare:

'ITC simultaneously determines all binding parameters (n, K, ΔH and ΔS) in a single experiment. When substances bind, heat is either generated or absorbed. ITC is a thermodynamic technique that directly measures the heat released or absorbed during a biomolecular binding event.

Measurement of this heat allows accurate determination of binding constants (KB), reaction stoichiometry (n), enthalpy (ΔH) and entropy (ΔS), thereby providing a complete thermodynamic profile of the molecular interaction in a single experiment.'

Features of the MIF iTC200

  • Directly measures sub-millimolar to nanomolar binding constants (102 to 109 M-1)
  • Measures nanomolar to picomolar binding constants (109 to 1012 M-1) using the competitive binding technique.
  • The sample cell is 200 µL. As little as 10 µg of protein can be used.

Resources

For excellent notes on setting up samples for ITC, see Vanderbilt University’s Center for Structural Biology ITC page. Note that the MIF instrument is a different model to that described, but the sample preparation notes are relevant.