• high quality

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  developed by the WHO Collaborating Centre in London

• high performance

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  detection limit 1 kU/L (1st British Standard 72/227)

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  between-assay CV better than 15% in range 2 - 135 kU/L

• low cost

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  all reagents are provided - only test tubes and water are required

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  uses inexpensive, robust equipment

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  each kit is sufficient for 100 assay tubes

• convenient

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  magnetic separation

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  shelf life of 1 year at 4-8°C

For information and prices please contact us.

The assay is an immunometric ('sandwich') EIA for the quantitative measurement of AFP in human serum or plasma. Sample AFP is bound by 2 anti-AFP antibodies directed at different epitopes. One antibody is attached to magnetic particles and the other is indirectly labelled with alkaline phosphatase using the biotin/streptavidin system. The assay has four main stages:

• Magnetic anti-AFP and biotinylated anti-AFP are incubated with sample (50 µL) for 12 - 24 hours at 4 - 8°C (overnight in a refrigerator) followed by a magnetic wash step.
• The magnetic particles are incubated with alkaline phosphatase labelled streptavidin for 1 hour at 4 - 8°C followed by 2 magnetic wash steps.
• A coloured enzyme substrate is incubated with the particles for 30 minutes at 37°C. The presence of alkaline phosphatase causes a colour change from yellow to pink. The reaction is terminated by addition of Stop Buffer.
• The tubes are then placed in the spectrophotometer or colorimeter. The optical density (at 550nm or 492nm) of each tube can be measured and the results calculated using a data processing program.

Incubation times	O/N + 30 mins + 30 mins
Standard Range	0-360 kU/L Standardised against 1st British Standard 72/227
Normal Ranges	Non-Pregnant female <25 |kU/L
Detection Limit	1   kU/L
Assay Reproducibility	Within-batch ±1SD kU/L %CV 2.3±0.2 6.9 9.0±0.4 4.9 16±0.6 3.7 140±7 5
Assay Reproducibility	Between-batch ±1SD kU/L %CV 2.7±0.3 12.3 9.4±0.3 3.0 16±0.8 4.9 135±12 8.9

AFP EIA Standards - see (*) AFP EIA Magnetic Antibody AFP EIA Biotinylated Antibody AFP EIA Enzyme Labelled Streptavidin AFP EIA Assay Buffer AFP EIA Wash Buffer

EIA Substrate Reagent EIA Substrate Buffer EIA Stop Buffer EIA Internal QC Sample Instruction booklet

(*) calibrated against 1st British Standard 72/227.

Test tubes, pipettes, multivortex mixer, magnetic separator, 37°C water-bath and a colorimeter or spectrophometer.