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Extinction Coefficient of Polymerized Diaminobenzidine Complexed with Cobalt As Final Reaction Product of Histochemical Oxidase Reactions

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Publisher Springer
Date 1995 Dec 1
PMID 8777734
Citations 1
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Abstract

The extinction coefficient is essential for the conversion of cytophotometric (mean integrated) absorbance values into absolute units of enzyme activity, for instance expressed in terms of moles of substrate converted per unit time and per unit wet weight of tissue. The extinction coefficient of polymerized diaminobenzidine (polyDAB) complexed with cobalt as the final reaction product of oxidase reactions was estimated at 575 nm by comparison of the amounts of final reaction products formed after incubation of serial unfixed cryostat sections of rat kidney to demonstrate D-amino acid oxidase activity with either the tetrazolium salt method or the cerium-DAB-cobalt-hydrogen peroxide method. Both procedures resulted in similar localization patterns of final reaction product in a granular form in epithelial cells of proximal tubules in rat kidney. The granules were peroxisomes. Linear relationships were found for both methods between the specific amounts of final reaction product generated by D-amino acid oxidase activity and incubation time. The cerium salt method gave rise to 7.4 times higher absorbance values of final reaction product generated per unit time and per unit wet weight of tissue than the tetrazolium salt procedure. The extinction coefficient of tetranitro BT-formazan is 19,000 at 557 nm. Therefore, the cytophotometric extinction coefficient of the polyDAB-cobalt complex as final reaction product of oxidase reactions was established to be 140,000.

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PMID: 8863047 DOI: 10.1007/BF02331433.

References
1.
Gossrau R, Frederiks W, Van Noorden C, Klebe S, Ruhnke M . Light microscopical detection of H2O2-generating oxidases using cerium ions and aqueous incubation media. Acta Histochem. 1991; 90(1):27-37. DOI: 10.1016/S0065-1281(11)80153-4. View

2.
Kooij A, Frederiks W, Gossrau R, Van Noorden C . Localization of xanthine oxidoreductase activity using the tissue protectant polyvinyl alcohol and final electron acceptor Tetranitro BT. J Histochem Cytochem. 1991; 39(1):87-93. DOI: 10.1177/39.1.1983876. View

3.
Angermuller S, Fahimi H . Heterogenous staining of D-amino acid oxidase in peroxisomes of rat liver and kidney. A light and electron microscopic study. Histochemistry. 1988; 88(3-6):277-85. View

4.
Frederiks W, Van Noorden C, Marx F, Gallagher P, Swann B . In situ kinetic measurements of D-amino acid oxidase in rat liver with respect to its substrate specificity. Histochem J. 1993; 25(8):578-82. View

5.
Van Noorden C, Jonges G . Molecular extinction coefficients of lead sulfide and polymerized diaminobenzidine as final reaction products of histochemical phosphatase reactions. Cytometry. 1992; 13(6):644-8. DOI: 10.1002/cyto.990130613. View