Biochemical tests are used to analyze a variety of blood components, and in the diagnosis and post- treatment follow-up of diseases. Diagnosis is often performed with an integrated approach using a number of clinical test items. It is necessary for the sound interpretation of measurement results to consider the mechanisms and pathogenesis, in addition to technical knowledge. Furthermore, some new pitfalls must be considered when introducing automatic analyzers. When considering re-examination, it is necessary to as- sess data of related test items, sample conditions, and all the possibilities of clinical backgrounds. Determin- ing data authenticity by the combination of pitfalls.of laboratory testing with clinical testing backgrounds may allow the work of clinical laboratory technologists to be more meaningful. [Review].