AN ALGORITHM FOR AUTOMATIC MOSAIC SPREAD ANALYSIS OF A PROTEIN CRYSTAL

The present paper describes the program MOSAICITY which assembles tool s developed for the mosaic spread analysis of protein crystals. This a nalysis, performed in an automatic and nonparametric way, combines wav elet filters and morphological treatment in order to localize reflecti ons in a diffraction pattern. The reflection intensities, rescaled acc ording to incidence-beam intensity and corrected for the background, a re measured using a fine rotation angle slicing. A Gaussian profile fi tting is performed. The angular width can be corrected for the Lorentz factor, beam divergence and energy resolution in order to obtain an e stimate of the mosaic spread of the crystal. For this last stage, a ne w analytical expression for the phi extent of the reflection range has been derived.