Multi-wavelength anomalous diffraction

Hendrickson, W. A., Pahler, A., Smith, J. L., Satow, Y, Merritt, E. A., and Phizackerley, R. P. (1989). Crystal structure of core streptavidin determined from multi-wavelength anomalous diffraction of synchrotron radiation. Proc. Natl. Acad. Sci. USA 86, 2190-2194. 

The tunability of synchrotron radiation allows for data collection at or near the x-ray absorption edge of anomalous scatterers present in the protein or crystal to provide experimental phase information. Using techniques such as multi-wavelength anomalous dispersion (MAD) and single-wavelength anomalous diffraction (SAD) researchers are now able to solve macromolecular structures in a matter of days or weeks, a process that required months, or even years, a decade ago. 

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