Biomolecular Interactions

Differential scanning calorimetry – DSC

Analysis of thermal transitions of various molecules in solution.

• Protein unfolding and refolding; melting temperatures and refolding efficiency.
• Lipid melting transition temperatures.

A solution of one molecule is placed in the sample cell, with a well-matched buffer sample in the reference cell. As the cells are heated, any transition due to a change in state requires differential heating of the two cells to maintain the temperature ramp. The amount of power required and the temperatures where it’s required tells us about changes in the structure of the molecules.

Analysis of the scans gives information about melting temperature, Tm, and aggregation or misfolding. DSC uses solutions of protein or lipids in aqueous buffers. Protein solutions at 1mg/ml often give good results. DSC is complementary to other thermal scanning assays of folding.

• Very flexible on buffer composition, allowing us to study protein folding in your buffer of choice including, e.g. high-salt and very complex formulations.
• Non-spectroscopic so even works with cloudy samples.
• Heating to >100°C, using a pressurised cell, for very stable molecules.
• Scan and re-scan, even overnight, to determine refolding efficiency.

The facility has a Microcal VP-DSC machine. More information at the Malvern Panalytical.

Plate reader

Quantitative assays using absorbance, fluorescence and luminescence optics for end-point and kinetic assays in microtitre plates. The facility has a BMG Labtech Polarstar Optima.