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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Food and Feed Safety Research » Research » Publications at this Location » Publication #312283
Title: Fluorescence polarization immunoassay using IgY antibodies for detection of valnemulin in swine tissue

Author
item ZHANG, HUIYAN - China Agricultural University
item MI, TIEJUN - China Agricultural University
item KHAN, OLEG YU - Moscow State University
item SHENG, YAJIE - China Agricultural University
item ERMIN, SERGEI - Moscow State University
item Beier, Ross
item ZHANG, SUXIA - China Agricultural University
item SHEN, JIANZHONG - China Agricultural University
item WANG, ZHANHUI - China Agricultural University

Submitted to: Analytical and Bioanalytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2015
Publication Date: 8/16/2015
Publication URL: http://handle.nal.usda.gov/10113/61618
Citation: Zhang, H., Mi, T., Khan, O.Y., Sheng, Y., Ermin, S.A., Beier, R.C., Zhang, S., Shen, J., Wang, Z. 2015. Fluorescence polarization immunoassay using IgY antibodies for detection of valnemulin in swine tissue. Analytical and Bioanalytical Chemistry. 407:7843-7848.

Interpretive Summary: A fluorescence polarization immunoassay (FPIA) for determination of valnemulin (VAL) in pork was developed and optimized. In an FPIA method, light is measured when a smaller molecule like VAL contains a fluorophore label. As the fluorophore-labeled VAL rotates in solution, it gives off light, and when the VAL binds to an antibody, and an egg yolk antibody was used here, the type of light drastically changes allowing one to make measurements of the amounts of VAL in solution. VAL is a semi-synthetic antibiotic intended exclusively for veterinary use. It is widely used for the treatment of respiratory and intestinal infections in pigs, poultry, and rabbits. There is concern for potential VAL residues in animal derived foods due to the adverse effects observed with VAL, inappetence, fever and ataxia. Immunoassays make use of antibodies and are used as an analytical tool to analyze for a specific compound. Antibodies are substances that are produced by the immune system in response to foreign substances which enter the body. Once the antibodies to a foreign substance are isolated, they can be used in a method to detect the presence of that foreign substance. A robust FPIA was developed and resulted in a detection limit of 26.4 ug/kg VAL. The developed FPIA using egg yolk antibody was used to analyze for VAL in pork tissue.

Technical Abstract: Immunoglobulin Y (IgY) is derived from egg yolk and has been identified as a cheap and high-yield immunoreagent. The application of IgY in immunoassay for the detection of chemical contaminants in food samples has rarely been reported. In this work, we describe a rapid and sensitive fluorescence polarization immunoassay (FPIA) for valnemulin (VAL) by using IgY that was produced using a previously prepared immunogen. Three fluorescein-labeled VAL tracers were synthesized and the sensitivity of the best tracer (VAL-DTAF) in the optimization FPIA with antibody IgY100 demonstrated an IC50 value of 11.8 ng/mL in buffer. After evaluation of several extraction procedures, acidic-acetonitrile was selected to extract VAL from pork tissue. The recoveries of VAL in spiked pork at levels of 50, 100, and 200 µg/kg were higher than 79.0% with CVs lower than 12%. The lowest detection limit (LOD) of the FPIA in pork was 26.4 µg/kg and was lower than the maximum residue limit (MRL) of VAL set by the European Commission. The study showed that IgY could be a good substitute for IgG when developing a high-throughput assay for chemical residues.