Comparison of Five Methods for Determination of 2,3-Diphosphoglycerate in Blood

摘要

Because the importance of 2,3-diphosphoglycerate in the regulation of the oxygen affinity of hemoglobin is recognized, there is growing need for a suitable method for determining this metabolite. Here we compare the colorimetric method of de Leeuw, two enzymatic rate-dependent methods (of Nygaard and R?rth and of Loos and Prins), and two enzymatic end-point methods (of Keitt and of Ericson and de Verdier). A good linearity was observed for all methods, up to 5.0 mmol of 2,3-diphosphoglycerate per liter of blood, except for the method of Ericson and de Verdier, for which an inexplicable upward drift in the calibration curve was found. Within-run precision in the duplicates and long-term precision in the methods of Loos and Prins and of de Leeuw were excellent. Mean analytical recoveries for all the methods ranged from 97 to 100%. In a paired comparison study of the methods, with the method of Loos and Prins as a reference, we did not find statistically significant differences. Coefficients of correlation were better than 0.990 ( P 0.0005).