Abstract
Recently, the measurement of folic acid by automated immunoassay analyzer system was performed for the routine clinical laboratory tests in patients with pernicious anemia and other diseases. Measurement of serum folic acid has been reported to be an easy and rapid assay and highly precision for routine tests using the automated immunoassay analyzer system. For these immunoassays, it becomes the problem in the mean folic acid concentration in serum by the difference of the standard samples and a difference of the measurement methods. On the other hand, it indicates that the standardization measurement may provide a useful tool to measure folic acid concentration if the folic acid measurement by LC/MS or LC/MS/MS will spread in its routine method.