Managing quality has always been a primary goal in the practice of clinical chemistry. Laboratorians have developed systems for quality control, quality assurance, and continuous quality improvement. Quality system design continues to evolve. These efforts are aimed at creating results such that each and every result is believable and thought to have been reported without errors. Others have studied the sources of errors throughout the testing cycle [1]. Ross and Boone have shown that 93% of the errors are either in the preanalytical or postanalytical portions of the process [2]. However, the 7% of errors occurring in the analytical portion are entirely the laboratory's responsibility and are the focus of this paper.
