Is it jolly SAD?

Examples of phasing macromolecular crystal structures based on single-wavelength anomalous dispersion (SAD) have demonstrated that this approach may have general applications in structural biology. With better data-collection facilities and cryogenic techniques, combined with powerful data-processing, phasing and density-modification programs, the SAD approach may prove simpler than phasing from multi-wavelength (MAD) measurements. It can be performed at any wavelength where anomalous scattering can be observed, in many cases using laboratory X-ray sources. However, there is still a need for accurate data, successful phase improvement and a certain amount of luck. This paper extends the discussion of Jolly SAD in Darner et al. [Dauter, Z., Dauter, M. & Dodson, E. (2002), Acta Cryst. D58, 494-506].