Direct spectrophotometry of magnesium in serum after reaction with hexokinase and glucose-6-phosphate dehydrogenase.
Open Access
- 1 May 1985
- journal article
- research article
- Published by Oxford University Press (OUP) in Clinical Chemistry
- Vol. 31 (5) , 703-705
- https://doi.org/10.1093/clinchem/31.5.703
Abstract
We describe a simple method for determining magnesium in serum by using hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49). The method is based on determination of the reaction rate of hexokinase activated by Mg2+, which participates in the hexokinase reaction as the substrate in the form of a Mg X ATP2- complex. The reaction rate is determined from the change in absorbance at 340 nm as NADPH is produced by the action of glucose-6-phosphate dehydrogenase. This simple and rapid spectrophotometric method does not require expensive instrumentation, but results correlate satisfactorily with those obtained by atomic absorption spectroscopy. Thus, the present method gives a "true" value for magnesium in serum, a value appreciably lower than that obtained by an earlier colorimetric method, the Xylidyl Blue II method (Biochem Med 7: 208-217, 1973), which lacks specificity.This publication has 1 reference indexed in Scilit:
- Determination of inorganic phosphorus using immobilized pyruvate oxidaseBiotechnology & Bioengineering, 1983