The Ultimate Wavelength for Protein Crystallography?

This paper describes an analysis of the optimum choice of the X-ray wavelength for macromolecular diffraction data collection. It is shown that there is no ultimate X-ray wavelength for protein crystallography and that the optimum wavelength depends to a large extent on the size of the protein crystal. It also depends on instrumental factors, such as efficiency of the detector for a particular wavelength and spectral density of the synchrotron radiation. Estimates of the optimum wavelength as a function of crystal size are given.