We have adapted for glucose determination a new approach to kinetic analyses [Anal. Chem. 50, 1611 (1978)]; it is 50-fold less dependent upon some experimental variables than is a more conventional rate method. Modification of a commercially available hexokinase/glucose-6-phosphate dehydrogenase reagent system for glucose provides that the rate of production of NADH be first-order in total glucose concentration within about 30 s after sample and reagent are mixed. In the kinetic method, absorbance vs. time data recorded after 30 s and a multiple-linear-regression program are used to compute the absorbance change that would occur if the reaction were monitored to completion. Results demonstrate a linear relationship between glucose concentration and computed absorbance change. Application of the method to 51 human sera without rigorous control of either temperature or reagent composition yielded a regression equation of y = 1.01x -0.3 when kinetic results (y) were compared with equilibrium results (x) for the same samples analyzed in a hospital laboratory.

We have adapted for glucose determination a new ap- proach to kinetic analyses (Anal. Chem. 50, 1611(1978)); it is 50-fold less dependent upon some experimental variables than is a more conventional rate method. Modi- fication of a commercially available hexokinase/glu- cose-6-phosphate dehydrogenase reagent system for glucose provides that the rate of production of NADH be first-order in-total glucose concentration within about 30 s after sample and reagent are mixed. In the kinetic method, absorbance vs. time data recorded after 30 s and a multiple-linear-regression program are used to compute the absorbance change that would occur if the reaction were monitored to completion. Results demonstrate a linear relationship between glucose concentration and computed absorbance change. Application of the method to 51 human sera without rigorous control of either tem- perature or reagent composition yielded a regression equation of y = 1.Olx- 0.3 when kinetic results (y) were compared with equilibrium results (x) for the same samples analyzed in a hospital laboratory. We report the establishment of conditions by which the hexokinase/glucose-6-phosphate dehydrogenase coupled- reaction system can be used for the kinetic determination of total glucose, and the adaptation of this reaction system to a new approach for kinetic analyses (1) in which dependencies upon experimental variables are much closer to equilibrium methods than to the more common kinetic methods. The re- action system becomes first-order in total glucose (a- and f3-D-glucose) in less than 30 s after sample and reagent are