Measurement errors and their consequences in protein crystallography

This article analyzes the relative impact of various types of measurement uncertainties on different stages of structure determination. The treatment of errors is an important part of the experimental process and becomes critical when data quality is barely sufficient to solve and/or answer detailed questions about the structure. The sources and types of experimental errors are described and methods of minimizing their impact are discussed. Practical calculations of sigma estimates in DENZO and SCALEPACK are presented.