Biosystems Total Iron Binding Capacity
TOTAL IRON BINDING CAPACITY (TIBC)
Fe3+ / MAGNESIUM HYDROXIDE CARBONATE
COD 11554 50 Tests
STORE AT 2-30ºC
Reagents for measurement of total iron binding capacity Only for in vitro use in the clinical laboratory
PRINCIPLE OF THE METHOD
Excess of Fe3+ is added to the sample to saturate serum transferrin. Uncomplexed Fe3+ is precipitated with magnesium hydroxide carbonate and the iron bonded to protein in the
supernatant is then spectrophotometrically measured1.
CONTENTS AND COMPOSITION
A. Reagent. 1 x 50 mL. Iron chloride (III) 0.12 mmol/L.
B. Reagent. 3.10 g. Magnesium hydroxide carbonate (powder). To be dispensed using the enclosed plastic spoon.
Store at 2-30ºC
Reagents are stable until the expiry date shown on the label when stored tightly closed and ifcontaminations are prevented during their use.
Indications of deterioration:
− Reagent A: Presence of particulate material, turbidity.
− Reagent B: Presence of moisture.
These auxiliary reagents are to be used together with the iron reagents contained in the
Biosystems Iron-ferrozine kit (cod 11509).
− Desktop centrifuge
− Analyzer, spectrophotometer or photometer able to read at 560 ± 20 nm.
Serum or heparinized plasma collected by standard procedures. Do not use hemolyzed samples.
The total iron binding capacity of serum or plasma is stable for 7 days at 2-8ºC.
1. Pipette into labelled tubes (Note 1):
Sample 0.5 mL
Reagent (A) 1.0 mL
2. Mix thoroughly and let stand for 5-30 minutes at room temperature.
3. Add to each tube one spoonful of Reagent (B).
4. Mix thoroughly and let stand the tubes for 30-60 minutes at room temperature. During thistime mix thoroughly several times.
5. Centrifuge at a minimum of 3000 r.p.m. for 10 minutes.
6. Carefully collect the supernatant (Note 2).
7. Measure the iron concentration in the supernatant, using the kit Iron-ferrozine (BioSystems, cod 11509).
Total Iron Binding Capacity (TIBC)
TIBC = Iron concentration in the supernatant x 3 (dilution)
Iron saturation iron saturation (%)
TIBC 100 serum iron concentration
Total Iron Binding Capacity (TIBC)2
Infant: 100-400 μg/dL = 18-72 μmol/L
Adult: 250-425 μg/dL = 45-76 μmol/L
These ranges are given for orientation only; each laboratory should establish its own reference ranges.
Each laboratory should establish its own internal Quality Control scheme and procedures for corrective action if controls do not recover within the acceptable tolerances.
− Detection limit 0.66 μg/dL iron = 0.12 μmol/L iron
− Linearity limit: 1000 μg/dL iron = 179 μmol/L iron. For higher values dilute sample 1/2 with distilled water and repeat measurement.
− Repeatibility (within run):Mean iron concentration CV n
250 μg/dL = 44.8 μmol/L 3.3 % 20
450 μg/dL = 80.6 μmol/L 1.9 % 20
− Reproducibility (run to run): Mean iron concentration CV n
250 μg/dL = 44.8 μmol/L 3.6 % 25
450 μg/dL = 80.6 μmol/L 2.4 % 25
− Sensitivity: 0.88 mA×dL/μg = 4,86 mA×L/μmol.
− Trueness: Results obtained with this reagent did not show systematic differences when compared with reference reagents (Note 3). Details of the comparison experiments are
available on request.
− Interferences: Bilirubin do not interfere. Do not use hemolyzed or lipemic sera. Other drugs and substances may interfere3.
These metrological characteristics have been obtained using an analyzer. Results may vary if a different instrument or a manual procedure are used.
Total iron binding capacity is a measure of the total amount of iron that serum proteins can combine. Nearly all the binding capacity is due to transferrin.
Normally, only about one third of the iron binding sites of transferrin are occupied by iron, so that serum transferrin has considerale reserve iron binding capacity.
A decrease in total iron binding capacity may be due to an hemochromatosis, acute iron poisoning, active cirrhosis or acute hepatitis2,4.
Total iron binding capacity is usually increased in iron deficiency anemia, however, measurement of total iron binding capacity or iron saturation should not be used as a test for
Clinical diagnosis should not be made on the findings of a single test result, but should integrate both clinical and laboratory data.
1. Contamination of glassware with iron will affect the test. Use acid-washed glassware or plastic tubes.
2. The supernatant can be stored for up to 1 hour at room temperature. lf the supernatant appears turbid, remove it apart and centrifuge again.
3. Calibration with the provided aqueous standard may cause a matrix related bias, specially in some analyzers. In these cases, it is recommended to calibrate using a serum based
standard (Biochemistry Calibrator, cod. 18011 and 18044).