The chromatic interference suppression of the Synermed® UIBC method is based upon the higher sensitivity of the chromogen used and the detection at a red wavelength, thus optimizing the signal to noise ratio.
Albumin binds with bromcresol green to form a colored complex. The absorbance of the complex is quantitated at 660 nm and is directly proportional to the albumin concentration in the sample.
In the Synermed UIBC reagent system, a known amount of ferrous iron is added, in excess, to the serum at an alkaline pH to enable saturation of the unoccupied iron binding sites on the transferrin molecule.
OH-
transferrin + Fe+2 -> transferrin-Fe complex + excess Fe +2
The ferrous ion that remains unbound to transferrin is then quantitated by complexing with the chromogen 3-(2-Pyridyl)-5,6-bis(2-[5-furylsulfonic Acid]-1,2,4-triazine to form a blue chromophore which absorbs in the near-infrared region of the spectrum. The absorbance of the blue iron-dye complex is proportional to UIBC concentration and is read spectrophotometrically at 600 nm.
excess Fe+2 + chromogen -> Fe+2-chromogen complex
(yellow) (blue)
Then by subtracting the amount of unbound iron thus measured from the total amount of iron originally added to the sample, the unsaturated iron-binding capacity may be determined.
To calculate the TIBC, perform a serum iron assay on the sample. Take the result obtained for the iron assay and add the UIBC result to obtain a value for TIBC.
UIBC levels will vary with age, sex, and diet. It is strongly recommended that each laboratory establish an expected range for the local population. The normal range for TIBC in adults is reported to be: 250-400 µg/dL.
Mean | SD | CV |
9.9 µmol/L (55 µg/dL) | 0.39 (2.2) | 4.0% |
41.1 µmol/L (229 µg/dL) | 0.33 (2.6) | 1.1% |
Mean | SD | CV |
10.3 µmol/L (57 µg/dL) | 0.46 (2.6) | 4.5% |
43.0 µmol/L (240 µg/dL) | 1.20 (6.7) | 2.8% |
Cat No. | Product Name | Packaging | Package Volume (mL) | Storage |
IR150-X | UIBC | 1x245 mL + 1x80 mL + 1x5 mL | 990 | 0-4° C |
IR150 | UIBC | 3x245 mL + 3x80 mL + 3x5 mL | 990 | 0-4° C |
IR151-L | UIBC Binding Buffer | 6x490 mL + 6x10 mL | 3,000 | 0-4° C |
IR152-L | UIBC Chromogen | 6x250 mL | 1,500 | 0-4° C |
IR150-WK | UIBC | 1x25mL + 1x7.2mL | 32.2 | 0-4° C |