Abstract
We evaluated ‘Lana® 1, 5AG Auto’ which were reagents for the measurement of 1, 5-anhydro-D-glucitol (1, 5AG) using an automated analyzer. In this method, pyranose oxidase (PROD) is used for oxidation of 1, 5AG and hydrogen peroxide resulted from oxidation of 1, 5AG is detected by colorimetry. Glucose is oxidized by PROD and highly interferes in the measurement of 1, 5AG. Therefore, in the reaction system, glucose is treated with glucokinase and is phosphorylated to form glucose-6-phosphate which is unreactive to PROD. In this study, we tested the influence of sugars other than glucose on the reagents of 1, 5AG. The presence of xylose, sorbose, galactose and gluconolactone interfered positively with the measurement of 1, 5AG. But these sugars exist rarely in normal serum, they have little effect on the measurement of serum 1, 5- AG. In constituents of the blood, heavy hemolysis and bilirubin interfered negatively with the measurement of 1, 5AG. The lower limit of detection was about 0.5mg/l. Measurements by the automated analyzer were highly correlated with those by a conventional column- enzyme method, and the former method was superior to the latter in both sensitivity and reproducibility. The measurement takes 10 min/test and have an ability of 600 tests/h. These findings indicate that the method is simpler and more precise in the measurement of 1, 5AG than the conventional method.
