It seems essentially all protein X-ray diffraction structures are obtained with flash-cooled protein crystals (in a stream of very cold gas). I’m curious if the diffraction pattern would be significantly different from the same crystal at room temperature (from thermal expansion, but not only - it may favor different conformations, and also flash cooling may disorder parts of the crystal).
What are some of the reasons that X-ray diffraction uses cooled crystals? Is it possible to do the same experiment with a room temperature crystal? Has this been done before, and what happens?