PRINCIPLE OF THE METHOD
Serum tranferrin is saturated with an excess of Fe3+ and the
unbound portion is precipitated with magnesium carbonate. The
total amount of iron is then determined. The difference between the
total iron-binding capacity (TIBC) and initial seric iron(SI) yields the
unsatured iron-binding capacity (UIBC)1,2
CLINICAL SIGNIFICANCE
The iron is the component of a great number of enzymes. The
myoglobin, muscular protein, contain iron, as well as the liver
Iron is necessary for the hemoglobin production, molecule that
transports oxygen inside red globules.
Serum iron is almost always accompanied by a measurement of
(TIBC) and denotes the available iron-binding sites of the serum.
We can found high levels in the ferropenic anemia.
Their deficit may be due to a hemochromatosis, cirrhosis or
hepatitis.1,5,6
Clinical diagnosis should not be made on findings of a single test
result, but should integrate both clinical and laboratory data.
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
- Samples centrifuge.
- General laboratory equipment (Note 1)
SAMPLES
Serum or heparinized plasma.
Free of hemolysis and separated from cells as rapidly as possible.
Stability of the sample: Iron is stable at 2-8ºC for 7 days1
PROCEDURE
1. Pipette into the tubes:
Sample (mL) 0.5
R 5 Saturating solution (mL) 1,0
2. Mix well and incubate for 10 min. at room temperature (15-
25ºC).
3. Add to each tube:
(*) R 6 Precipitating agent (spoonful) 3
(*) Powder: Dispense using the enclosed spoon. (Dosage: aprox. 70 mg)
4. Mix well and incubate for 10 min. at room temperature (15-
25ºC).
5. Centrifuge 15 min. at 3000 r.p.m.
6. Collect the supernatant carefully and measure the iron
concentration (Note 2)
See: ADDITIONAL REAGENTS
CALCULATIONS
The calculations are indicating in the Iron Insert determination.
TIBC = Iron concentration in the supernatant x 3 (Dilution factor)
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.
REFERENCE VALUES4
Serum or plasma:
200 – 400 g/dL
36-72 mol/L
These values are for orientation purpose; each laboratory should
establish its own reference range.
PERFORMANCE CHARACTERISTICS
Measuring range: From Iron detection limit: 0,850 μg/dL to Iron linearity
limit: 1000 μg/dL. If the results obtained were greater than linearity limit,
dilute the sample 1/2 with NaCl 9 g/L and multiply the result by 2.
INTERFERENCES
Hemolyzed samples are rejected, since erythrocytes contain iron and
therefore falsely elevate the serum results1
.
A list of drugs and other interfering substances with iron determination
has been reported by Young et. al3,4
.
NOTES
1. It is recommended to use disposable material. If glassware is used
the material should be soaking for 6 h in diluted HCl (20% v/v) and
then thoroughly rinsed with distilled water and dried before use.
2. The supernatant is stable up to 1 hour at room temperature. If
appear turbid, centrifuge again.
3. SPINREACT has instruction sheets for several automatic
analyzers.
