A microfabrication-based approach to quantitative isothermal titration calorimetry

Area of Science:

• Biophysical Chemistry
• Analytical Chemistry
• Microfluidics

Background:

• Isothermal titration calorimetry (ITC) is crucial for determining biomolecular binding properties but conventional instruments are costly and time-consuming.
• Existing microfabricated calorimetric devices lack the accuracy for quantitative ITC measurements of biochemical reactions.

Purpose of the Study:

• To present a novel microfabrication-based approach for integrated, quantitative ITC characterization of biomolecular interactions.
• To develop a microdevice enabling accurate and efficient ITC measurements with reduced sample consumption and analysis time.

Main Methods:

• Integration of microfabricated differential calorimetric sensors with microfluidic titration systems.
• Differential measurement of reaction thermal power in well-defined, thermally isolated micro-volumes.
• Application of the microdevice for characterizing protein-ligand interactions under isothermal conditions.

Main Results:

• Demonstrated accurate ITC characterization of 18-Crown-6 with barium chloride and ribonuclease A with cytidine 2'-monophosphate.
• Achieved measurements in small reaction volumes (approx. 0.7 µL) and at low concentrations (down to 2mM).
• Obtained complete thermodynamic profiles in reduced analysis times and with lower material consumption, consistent with published data.

Conclusions:

• The microfabrication approach enables accurate, quantitative, and efficient ITC measurements of biomolecular interactions.
• This technology holds significant potential for advancing biomolecular characterization in biomedical research and applications.
• The developed microdevice offers a cost-effective and rapid alternative for thermodynamic profiling of molecular binding.