2. Academic Validation
  3. A Zinpyr-1-based Fluorimetric Microassay for Free Zinc in Human Serum

A Zinpyr-1-based Fluorimetric Microassay for Free Zinc in Human Serum

  • Int J Mol Sci. 2019 Aug 16;20(16):4006. doi: 10.3390/ijms20164006.
Wiebke Alker 1 2,  Tanja Schwerdtle 2 3,  Lutz Schomburg 2 4,  Hajo Haase 5 6
Affiliations

Affiliations

  • 1 Department of Food Chemistry and Toxicology, Berlin Institute of Technology, 13355 Berlin, Germany.
  • 2 TraceAge-DFG Research Unit on Interactions of essential trace elements in healthy and diseased elderly, Potsdam-Berlin-Jena, Germany.
  • 3 Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany.
  • 4 Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany.
  • 5 Department of Food Chemistry and Toxicology, Berlin Institute of Technology, 13355 Berlin, Germany. [email protected].
  • 6 TraceAge-DFG Research Unit on Interactions of essential trace elements in healthy and diseased elderly, Potsdam-Berlin-Jena, Germany. [email protected].
PMID: 31426452 DOI: 10.3390/ijms20164006
Abstract

Zinc is an essential trace element, making it crucial to have a reliable biomarker for evaluating an individual's zinc status. The total serum zinc concentration, which is presently the most commonly used biomarker, is not ideal for this purpose, but a superior alternative is still missing. The free zinc concentration, which describes the fraction of zinc that is only loosely bound and easily exchangeable, has been proposed for this purpose, as it reflects the highly bioavailable part of serum zinc. This report presents a fluorescence-based method for determining the free zinc concentration in human serum samples, using the fluorescent probe Zinpyr-1. The assay has been applied on 154 commercially obtained human serum samples. Measured free zinc concentrations ranged from 0.09 to 0.42 nM with a mean of 0.22 ± 0.05 nM. It did not correlate with age or the total serum concentrations of zinc, manganese, iron or selenium. A negative correlation between the concentration of free zinc and total copper has been seen for sera from females. In addition, the free zinc concentration in sera from females (0.21 ± 0.05 nM) was significantly lower than in males (0.23 ± 0.06 nM). The assay uses a sample volume of less than 10 µL, is rapid and cost-effective and allows us to address questions regarding factors influencing the free serum zinc concentration, its connection with the body's zinc status, and its suitability as a future biomarker for an individual's zinc status.

Keywords

Zinypr-1; biomarker; fluorescent probe; free zinc; serum; zinc.

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