Proficiency survey of serum protein analyses in Scandinavia

A lyophilized human pool serum was distributed to Scandinavian clinical chemical laboratories for routine quantitation of different serum proteins. The analytical repertoir of the laboratories, and the methods and reference materials used, were registered. For almost all proteins the results varied considerably between the laboratories (CV 8--29%). The reasons for this variation are discussed together with possible recommendations to improve the accuracy of protein measurements.