Zinc Assay Reagents

Reliable zinc assay for nutritional and clinical diagnostics.
Detects zinc deficiency or elevation with high accuracy in serum, plasma and urine samples.

High-Sensitivity Zinc Detection for Nutritional Deficiency and Disease Monitoring

Zinc is an essential trace element involved in numerous biological functions, particularly as a cofactor in various metalloenzymes. Zinc deficiency may lead to dermatitis, impaired taste and smell, poor wound healing, and growth disturbances. Causes of deficiency include malabsorption (e.g. liver or kidney disease), increased excretion, or chronic illness. Conversely, elevated levels may occur in conditions such as hemolytic anemia or eosinophilia.

The NAGASE zinc assay enables sensitive and accurate quantification of zinc in serum, plasma and urine. It features a wide linearity range (2–500 µg/dL), high repeatability, and minimal interference. The method shows strong correlation with ICP-MS and allows for direct urine testing without preprocessing.

NAGASE supplies zinc assay reagents in bulk for clinical diagnostics and OEM applications.

Applications

The zinc assay is suitable for a wide range of clinical and nutritional diagnostic settings.

  • Assessment of zinc deficiency in patients with malabsorption or chronic disease
  • Monitoring zinc levels in serum or urine for nutritional studies
  • Diagnosis of taste or smell disorders linked to trace element deficiency
  • Evaluation of delayed wound healing and growth disturbances
  • Supportive testing in liver, kidney, or metabolic conditions

Features

The zinc assay provides precise, interference-resistant performance for serum, plasma and urine analysis.

  • Wide linear range – 2 to 500 µg/dL for flexible testing across concentrations
  • Excellent correlation – Matches well with ICP-MS reference method
  • Minimal interference – Coexisting substances have low impact
  • Direct urine measurement – No sample preparation required
  • Long reagent stability – At least 8 weeks after opening

Intended Use

Our reagents are specifically designed for the in vitro-quantitative determination of Zinc in human serum, plasma and urine.

Principle of the Method

The concentration of zinc in a sample is measured by analyzing the change in absorbance that occurs when zinc (Zn2+) in the specimen forms a complex with 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamin-o)phenol sodium salt (5-Br-PAPS), using a spectrophotometric analysis instrument.

Assay Procedure

Individual instrument applications are available on request.

Measurement timeline for zinc assay on TBA-120FR: Reagent 1 and specimen added at 0 min, Reagent 2 at 5 min for blank measurement, followed by sample measurement at 10 min. Absorbance measured at 548 nm (main) and 700 nm (sub).

Assay Reagents, Storage and Stability

Reagent 1: Buffer
Reagent 2:  5-Br-PSAP
Both reagents are liquid, ready to use

Storage: 2-10 °C
Shelf Life: 12 months (before use)
Stability after Opening: at least 8 weeks at 2-10 °C

Performance Data

The following performance data were obtained on a TBA-120FR clinical analyzer.

Method Comparison
Comparison studies were carried out using another similar commercially available method. The following results were obtained.

Correlation graph comparing NAGASE zinc assay with ICP-MS reference method in serum samples (n = 50), showing strong agreement with r = 0.9996.
Correlation plot showing zinc levels measured by NAGASE assay versus another direct commercial reagent in serum (n = 65), with r = 0.9999 and slope ≈1.015.
Linear regression of NAGASE zinc assay against a second commercial direct reagent in serum (n = 65), demonstrating high correlation (r = 0.9999) across 0–600 µg/dL.

Sensitivity
The sensitivity was evaluated by reading the change in absorbance for purified water sample and standard solution with known concentrations. The results indicated that Zn showed little or no reagent drift on a zero sample.
Under the reaction condition described, 200 µg/dL standard solution gives a  ΔABS of 0.04-0.24.

Linearity

Low Range

Linearity graph of the zinc assay in the low concentration range (0–100 µg/dL), showing a strong linear response across a 10-fold dilution series.

High Range

Linearity graph of the zinc assay in the high concentration range (0–1000 µg/dL), confirming accurate performance over wide dilution ratios.

Precision (within-run)

Table showing within-run precision of zinc assay for two serum and two urine samples (n = 20), including mean, min, max, range, standard deviation (SD), and coefficient of variation (CV%).

Interfering Substances

Graphs showing that potential interfering substances—including ascorbic acid, chyle, hemolytic hemoglobin, EDTA, free and conjugated bilirubin, copper (Cu), and iron (Fe)—have minimal impact on zinc assay results, confirming assay robustness and specificity.

Frequently Asked Questions about Zinc Assay Reagents

Why is zinc measured in clinical diagnostics?
Zinc is essential for immune function, wound healing, and enzymatic activity. Deficiency may lead to various clinical symptoms including dermatitis, taste disturbances, and growth disorders.

How is zinc measured in this assay?
The NAGASE assay uses a high-linearity, interference-resistant method that correlates well with ICP-MS and allows direct measurement in serum, plasma and urine.

What are common causes of low zinc levels?
Zinc deficiency can result from malabsorption, liver or kidney disease, increased demand, or chelating therapies. Conditions like acrodermatitis enteropathica and hypogonadism are also relevant.

Can high zinc levels be clinically significant?
Yes. Elevated zinc levels may be associated with hemolytic anemia or eosinophilia and should be evaluated in appropriate clinical context.

Is the reagent suitable for OEM and long-term use?
Yes, the opened reagent remains stable for at least 8 weeks and is available in bulk for OEM integration and clinical labs.

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In Vitro Diagnostics

Aziza Aknin
Key Account Manager