Nutritional zinc deficiency in humans is fairly prevalent throughout the world,
deficiency is characterized by growth retardation in children and
adolescents, hypogonadism in males, mild dermatitis, poor appetite,
delayed wound healing, abnormal dark adaptation, and mental lethargy and
impaired immune responses.
Clinical diagnosis should not be made on a single test result; it should
integrate clinical and other laboratory data.
PRINCIPLE OF THE METHOD
Direct colorimetric test without deproteinization of the sample. At pH 8.6, in
a buffered media, zinc reacts with the specific complexant 5-Br-PAPS, forms
a stable coloured complex.
The colour intensity is proportional to the amount of zinc present in the
sample1,2.
STORAGE AND STABILITY
All the components of the kit are stable until the expiration date on the label
when stored tightly closed at 2-8ºC, protected from light and contaminations
prevented during their use.
Do not use reagents over the expiration date.
Signs of reagent deterioration:
- Presence of particles and turbidity.
ADDITIONAL EQUIPMENT
- Spectrophotometer or colorimeter measuring at 560 nm.
- Matched cuvettes 1,0 cm light path.
- General laboratory equipment(Note 2).
SAMPLES
- Serum or plasma1
: Not haemolysed. Use only heparin salts as
anticoagulants. Stability: 7 days at 2-8ºC.
- Seminal fluid: Centrifuge the sample at 3000 r.p.m. for 10-15 minutes.
Dilute supernatant 1/100 with NaCl 9 g/L and multiply the result by 100.
Stability: 7 days at 2-8ºC.
QUALITY CONTROL
Control sera are recommended to monitor the performance of assay procedures:
SPINTROL H Normal and Pathologic (Ref. 1002120 and 1002210).
If control values are found outside the defined range, check the instrument,
reagents and calibrator for problems.
Each laboratory should establish its own Quality Control scheme and corrective
actions if controls do not meet the acceptable tolerances.
PERFORMANCE CHARACTERISTICS
Measuring range: From detection limit of 3,6 g/dL to linearity limit of 2012 g/dL.
If the results obtained were greater than linearity limit, dilute the sample 1/10 with
NaCl 9 g/L and multiply the result by 10.
INTERFERENCES
No interferences were observed to bilirubin up to 15 mg/dL, hemoglobin up to 0,5
g/dL and triglycerides up to 1000 mg/dL.
EDTA interfere in the test.
A list of drugs and other interfering substances with zinc determination has been
reported3,4.
NOTES
1. ZINC CAL: Proceed carefully with this product because due its nature it can
get contamined easily.
2. It is recommended to use disposable material. If glassware is used the
material should be scrupulously cleaned with hydrochloric acid 1 N and then
thoroughly rinsed it with distilled water.
3. Use clean disposable pipette tips for its dispensation.
4. SPINREACT has instruction sheets for several automatic analyzers.
Instructions for many of them are available on request.
