Clinical Chemistry, Vol 40, 763-767, Copyright © 1994 by American Association for Clinical Chemistry

New enzymatic assay of iron in serum

T Fujita, H Hamasaki, C Furukata and M Nonobe
Biochemical Research and Development Center, Oriental Yeast Co., Ltd., Osaka, Japan.

A new enzymatic method for assaying iron in serum samples, suitable for automated analyzers, is reported. Three reagent mixtures are used: dilution buffer (pH 3.0; ascorbate), reagent 1 (pH 6.7; apoaconitase), and reagent 2 (pH 7.7; citrate, magnesium, and isocitrate dehydrogenase). Sera are diluted with dilution buffer. Fe3+ is liberated from transferrin in sera under acidic conditions, and then reduced by ascorbate. Reagent 1 is added to diluted specimens, and apoaconitase is reactivated by Fe2+ at neutral pH. The resulting solutions are mixed with reagent 2, so that holoaconitase hydrolyzes citrate to isocitrate and the isocitrate and NADP+ are converted to 2- oxoglutarate, NADPH, and CO2. Serum iron is determined linearly up to 70 mumol/L, with within-run CVs < or = 2.4% and day-to-day CVs < or = 2.9%. This method (y) gives results correlating with those of a Reference Method (x) proposed by the International Committee for Standardization in Haematology: y = 0.98x + 0.38 mumol/L (n = 72, r = 0.996, Sylx = 0.63 mumol/L). The mean (+/- SD) serum iron concentrations measured by our method were 18.5 +/- 5.4 and 15.2 +/- 6.0 mumol/L for 63 males and 166 females, respectively.

The following articles in journals at HighWire Press have cited this article:

				H. Yamanishi, S. Kimura, S. Iyama, Y. Yamaguchi, and T. Yanagihara Fully automated measurement of total iron-binding capacity in serum Clin. Chem., December 1, 1997; 43(12): 2413 - 2417. [Abstract] [Full Text] [PDF]