Abstract
Various methods (microbiological assay, radioisotope dilution assay, high-performance liquid chromatography, chemiluminescence assay and so on) are used for vitamin B_<12> determination in foods and clinical materials. Although a biosensor based on surface plasmon resonance has been devised in the field of food analysis, the traditional microbiological assay is even now used worldwide. Human serum vitamin B_<12> was routinely determined by three fully-autoanalyzers: the ADVIA Centaur immunoassay system, Access immunoassay system, and Elecsys system are available in Japan. There are various problems to establish standardization of human serum vitamin B_<12> assay by these clinical laboratory analyzers.
