TABLE 10.

Advantages and disadvantages of the main methods used to measure serum-based iron status indicators¹

Indicator	Method	Advantages	Disadvantages
Serum iron, TIBC, or UIBC	Colorimetric assay	• Requires relatively inexpensive photometric instrument	• Manual multistep assay
		• Relatively inexpensive	• Requires fairly high sample volume (≥500 µL)
			• Rigorous elimination of iron contamination
			• Moderate precision
	Clinical chemistry analyzer (colorimetric)	• High sample throughput	• Typically requires sample volume of ≥150 µL
		• Quick turnaround time to first result	• No control over lot-to-lot variability or assay recalibration/reformulation
		• Available in commercial kit form for several instrument platforms	• Moderately expensive instrumentation
		• Minimum operator involvement	• Instrumentation requires regular maintenance and periodic technical service
		• Good precision
		• Relatively low reagent cost
	Atomic absorption spectrophotometry	• Relatively simple processing	• Relatively expensive instrumentation
		• Quick analysis time	• Instrumentation requires regular maintenance and periodic technical service
		• Good precision
Serum transferrin	Immunoassay on analyzer	• High sample throughput	• Typically requires sample volume of ≥150 µL
		• Quick turnaround time to first result	• No control over lot-to-lot variability or assay recalibration/reformulation
		• Available in commercial kit form for several instrument platforms	• Moderately expensive instrumentation
		• Minimum operator involvement	• Instrumentation requires regular maintenance and periodic technical service
		• Good precision
Serum ferritin	ELISA assay	• Requires small to moderate sample volume (50–100 µL)	• Manual assay; several pipeting steps; adherence to strict timing
		• Requires relatively inexpensive microplate reader (450 ± 10 nm filter)	• Plate washer is recommended; insufficient washing may result in poor precision
		• Available in commercial kit form from several manufacturers	• Moderate precision (duplicates recommended)
			• Reagent cost can be moderately high
	Immunoassay on analyzer	• High sample throughput	• Typically requires sample volume of ≥150 µL
		• Quick turnaround time to first result	• No control over lot-to-lot variability or assay recalibration/reformulation
		• Available in commercial kit form for several instrument platforms	• Moderately expensive instrumentation
		• Minimum operator involvement	• Instrumentation requires regular maintenance and periodic technical service
		• Good precision
		• Relatively low reagent cost
Serum soluble transferrin receptor	ELISA assay	• Requires small sample volume (≤50 µL) • Requires relatively inexpensive microplate reader (450 ± 10 nm filter plus second filter for 550–650 nm) • Available in commercial kit form from few manufacturers	• Manual assay; several pipetting steps; adherence to strict timing • Plate washer is recommended; insufficient washing may result in poor precision • Moderate precision (duplicates recommended) • Reagent cost can be moderately high
	Immunoassay on analyzer	• High sample throughput	• Typically requires sample volume of ≥150 µL
		• Quick turnaround time to first result	• No control over lot-to-lot variability or assay recalibration/reformulation
		• Available in commercial kit form for several instrument platforms	• Moderately expensive instrumentation
		• Minimum operator involvement	• Instrumentation requires regular maintenance and periodic technical service
		• Good precision	• Moderately high reagent cost

¹TIBC, total iron-binding capacity; UIBC, unsaturated iron-binding capacity.