Thermal shift assays, or differential scanning fluorimetry (DSF), confirm a compound's engagement with a target protein by evaluating shifts in protein melting temperature. The assay is performed in a high-throughput format in 96-well plates.
Proteins are subject to a temperature gradient in the presence of a fluorescent probe, SYPROTM, that is quenched by water. As the proteins unfold, their exposed hydrophobic domains bind the dye resulting in increased fluorescence until they began to aggregate and exclude the dye with a corresponding decrease in fluorescence.