Cool data: quantity AND quality

The use of cryo-techniques in macromolecular crystallography has increased enormously over the last eight years and has become a vital part of modern X-ray data-collection methods. This paper presents some reasons fbr the ris e in popularity of cryo-techniques and a brief outline of the basic methods , followed by a detailed discussion of factors to be considered when trying to optimize both the quantity and quality of the data collected. As more e xperimenters at synchrotrons observe significant radiation damage to crysta ls held near 100 K, the available options for further prolonging crystal li fetime and extending the techniques become worth investigating. Some possib ilities and parameters to be considered are presented, although these must remain speculative until more experimental data are available.