Description
Enzyme immunoassay for the quantitative determination of Alpha-Fetoprotein (AFP) in human serum or plasma samples. Quality controls are included with the kit. Developed and manufactured in Europe by PromedeusLab.
Summary
Alpha-fetoprotein (AFP) is a 70-kDa tumor-associated fetal mammalian glycoprotein which belongs to the gene family of serum albumin. AFP is involved with both ontogenic and oncogenic growth, as well as immunoregulatory processes (1). AFP is synthesized in the yolk sac, fetal liver, and gastrointestinal tract during pregnancy but is re-expressed in multiple adult tumors of mixed mesodermal/endodermal origin (2). Native AFP during pregnancy as well as tumour AFP stimulates cell and tissue growth, thus tAFP supports oncogenesis. Serum levels of AFP are elevated in patients with liver cancer as well as other types of cancer (breast, esophagus, cervical, pancreatic, endometrial, gastric, lung, rectum), and noncancer diseases such as cirrhosis, nephrotic syndrome, and gastritis. On the other hand, patients suffering from multiple myeloma, Wilms' tumor, and 22 other types of noncancer diseases had significantly decreased median serum AFP levels than that of healthy controls (3). Alpha-fetoprotein is a shuttle protein that delivers nutrients through receptor-mediated endocytosis to embryotic cells. In adults, AFP can shuttle drugs into alpha-fetoprotein receptor-positive myeloid-derived suppressor, regenerating and cancer cells (4).
Other Names
Alpha Fetoprotein, Alpha-1-fetoprotein, Alpha-fetoglobulin, HPAFP, α-fetoprotein, alpha fetal protein, UniProtKB# P02771.
Principle of Method
The microtiter plate is coated with the antibody specifically binding Alpha fetoprotein. The human serum and plasma are incubated in the plate with the capture antibody.
The specimen is washed out and the specifically bound protein is incubated with biotin-labelled detection antibody. Following another washing step, Streptavidin-HRP conjugate is added into the well. Unbound reagent is then washed out. Horseradish peroxidase (HRP) bound in the complex reacts with the chromogenic substrate (TMB) creating the blue colour. The reaction is stopped by addition of STOP solution (H2SO4).
The absorbance values are measured at 450 nm (optionally 450/630 nm) and are proportional to the concentration of AFP in the specimen. The concentration of AFP in unknown samples is determined from the calibration curve which is created by plotting the absorbance values against the standard concentration values.
Sample Types
Serum, Plasma
Typical Standard Curve
Assay Range: 0.3125 ng/mL - 20 ng/mL
Sensitivity
The limit of detection, defined as a concentration of human AFP giving absorbance higher than absorbance of blank + 3 standard deviations, is better than 0.08 ng/mL of sample.
Precision
Intra-Assay
| Test sample | Mean (ng/mL) | SD | CV |
| 1 |
54.8 |
4.1 |
7.5% |
| 2 |
79.6 |
3.8 |
4.8 |
Inter-Assay (Run-to-Run)
| Test sample | Mean (ng/mL) | SD | CV |
| 1 |
5.8 |
0.16 |
2.8% |
| 2 |
3.6 |
0.02 |
5.4% |
Accuracy
Dilution Linearity:
| Test sample | Dilution |
Measured Concentration (ng/mL) |
Expected Concentration (ng/mL) |
Yield |
| 1 |
55.5 |
- | - | |
| 1 | 2x | 28.4 |
27.7 |
102% |
| 1 | 4x | 14.0 |
13.9 |
101% |
| 1 | 8x | 6.6 |
6.9 |
96% |
| 2 |
58.3 |
- |
- | |
| 2 | 2x | 28.1 |
29.2 |
96% |
| 2 | 4x | 14.2 |
14.6 |
98% |
| 2 | 8x | 6.6 |
7.3 |
90% |
Spiking Recovery:
| Test sample | Spike (ng/mL) |
Measured Concentration (ng/mL) |
Expected Concentration (ng/mL) |
Yield |
| 1 |
- | 6.2 |
- | - |
| 1 | 50 |
50.0 |
56.2 |
89% |
| 1 | 25 |
27.3 |
31.2 |
88% |
| 1 | 12.5 |
16.5 |
18.7 |
88% |
Storage
The kit must be stored at 2–8 °C. The opened components can be stored for one week at 2–8 °C.
Usage
This assay is for in vitro research use only and is not for use in diagnostic procedures.
Resources
Summary References
- Adigun OO, Yarrarapu SNS, Zubair M, Khetarpal S. Alpha Fetoprotein. 2023 Jan 18. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 28613501.
- Wong RJ, Ahmed A, Gish RG. Elevated alpha-fetoprotein: differential diagnosis - hepatocellular carcinoma and other disorders. Clin Liver Dis. 2015 May;19(2):309-23. doi: 10.1016/j.cld.2015.01.005. Epub 2015 Feb 27. PMID: 25921665.
- He Y, Lu H, Zhang L. Serum AFP levels in patients suffering from 47 different types of cancers and noncancer diseases. Prog Mol Biol Transl Sci. 2019;162:199-212. doi: 10.1016/bs.pmbts.2019.01.001. Epub 2019 Mar 6. PMID: 30905450.
- Pak VN. The use of alpha-fetoprotein for the treatment of autoimmune diseases and cancer. Ther Deliv. 2018 Jan;9(1):37-46. doi: 10.4155/tde-2017-0073. PMID: 29216804.
Ilex Life Sciences LLC is an authorized distributor of PromedeusLab.