Cryocrystallography of biological macromolecules

X-ray diffraction experiments on crystals of biological macromolecules, especially when carried out on highly intense synchrotron beam lines, frequently suffer from radiation damage. Performing such experiments at cryogenic temperatures virtually eliminates radiation damage thus producing higher quality diffraction data and often making previously intractable problems feasible. In the following article the most important experimental aspects of low temperature diffraction experiments on macromolecular crystals will be discussed.