Abstract
We have found that the Lana AG® kit used for determination of 1, 5-anhydroglucitol in plasma or serum interfered with the intravenous infusion of maltose, which rarely exists in normal plasma. The principle of the kit consists of the removal of interfering substances with a mini-column, an oxidation of the recovered 1, 5-anhydroglucitol by pyranose oxidase and a detection of the hydrogen peroxide with a color development reaction. At the detection system, glucose is a major interfering sugar but it is completely trapped in the mini-column. Because of the lower affinity of the mini-column for maltose, infused maltose leaks out of the mini-column slightly. As the pyranose oxidase does not react with maltose, it is stipulated that pyranose oxidase is contaminated with maltase. The leaked maltose is hydrolyzed into glucose with maltase and the formed glucose is oxidised with pyranose oxidase and changes color.
