Differential scanning calorimetry can give an absolute measure of protein thermostability. Thermofluor can assess the relative thermostability of a protein in different solvent conditions.
Using Thermofluor, one may find that if the protein melts below 45 degrees Celsius that crystallization may be difficult or unsuccessful. Or it could indicate that one may set the crystallization experiments at temperatures below room temperature, such as 4 degrees Celsius. That being said, a protein melting above 45 degrees Celsius does not guarantee crystallization success. There are many other variables to consider in crystallization besides protein melting temperatures.
Thermofluor can be used to screen pH, buffer type and solubilizing agents when searching for reagent conditions that promote sample stability. Protein stability can be an important crystallization variable and Thermofluor can allow one to rapidly screen many different pH levels, buffer types and solubilizing agents towards optimizing a sample buffer that promotes optimal sample solubility.
In addition to the melting temperature one should also consider the shape of the melting curve. A very high initial flourescence can indicate a partially unfolded protein or hydrophobic patches on the surface of the protein. A very low initial flourescence can be a good sign compact proteins. A steep transmission curve is often considered better than a shallow surve.
As a fluorescence reporter may likely interact differently with exposed hydrophobic patches in different proteins, one might be a bit more careful in comparing the Thermofluor results between different proteins. Yet, it can be a tool for reasonable comparison between proteins.
Solubility & Stability Screen
Evaluate protein solubility, stability and crystallization in the presence of 94 different chemical additives sampling 17 different classes of reagents plus two controls.
Solubility & Stability Screen 2
Designed to assist in the identification of optimal buffer, pH and ionic strength formulations that promote protein solubility and stability.
Evaluate 20 different buffer types from pH 3.5 to 9.6 in 0.1 pH increments.