The measurands to be studied, the instrument(s) and methods of analysis, including any reference methods, standards or calibrators to which these may be linked, and the units of reporting for each measurand should be reported.  If a reference interval for the measurand in the laboratory in which the study is conducted is available, this should be included.  A brief summary of the quality control and quality assurance applied and the acceptability of performance, preferably based on quality control validation to provide a high probability of error detection, should be provided in order to ensure that there is stable instrument performance for the duration of the study. This is particularly important for those measurands that cannot be frozen and therefore must be run on the same day as collection.