IgY Polyclonal Antibodies

IgY antibody development is GenWay's specialty. Chicken IgY polyclonal antibodies have higher avidity, higher specificity and lower cross-reactivity as compared to IgG antibodies. One further unique feature of IgY antibodies is that they have a broader antigen-binding host range, due to the great evolutionary distance between chickens and mammals.

GenWay has produced over 1,500 polyclonal IgY antibodies with a very high success rate. Our technology yields mono-specific polyclonal IgY antibodies through bioinformatics-assisted antigen selection, expression, and purification, and ligand affinity column purification of total IgY antibodies.

Part of the uniqueness of GenWay's antibodies is that they are generated against recombinant protein domains of 50-300 amino acids in length, much larger than the typical peptide antigen of only 6-20 amino acids. The result of these high quality larger epitope antigens is a mono-specific polyclonal antibody that is useful for various applications.

One of the key steps of GenWay's IgY production is to use antigen-affinity chromatography to generate highly-specific antibodies (Figure 1).


Figure 1. Outline process of GenWay IgY production.

The antigen-affinity chromatography process ensures high quality of the polyclonal IgY antibodies. 

Figure 2. Key Points of Difference in IgY and IgG

IgY antibodies have a different structure from IgG, particularly in the Fc and hinge regions. The affinity maturation process of IgY is also different from IgG. These biological features underlie IgY's competitive advantages over IgG. Shown in the four panels are several comparisons between IgY and IgG.

Despite the overall similarities between IgY and IgG antibodies, there are some profound differences in their chemical structures and biological features (Figure 2). The IgY Fc region also has an additional pair of carbohydrate chains with unique sugar residues, important for highly efficient covalent coupling to solid surfaces such as microbeads or arrays. The affinity maturation process of IgY is via gene conversion, different from that of IgG, which is via somatic mutation. The phylogenetic distance between chickens and mammals often makes the chicken immune system far more responsive to mammalian protein antigens thus generating highly reactive antibodies, particularly targeted to conserved proteins, against which IgGs are difficult or impossible to raise. The IgY production process is non-invasive and accumulative from collecting eggs, in contrast to that of IgG, which requires bleeding and collecting sera from immunized animals. The productivity of IgY is also superior, since a single egg can generate about 100 mg of total IgY, about the yield of 50-100 mice.

In summary, IgY antibodies have advantages over IgG antibodies, including high specificity, strong avidity, scalable productivity, low assay background, and applicability to many immunoassays. More specifically, GenWay's products and IgY antibodies have the following features:

  • GenWay's antibodies are domain-specific, which are raised against a target of 50-300 amino acids to full-length, which is at least 5 times greater than the target size of peptide antibodies - usually about 20 amino acid residues. Compared to the success rate of peptide antibodies (currently <50%), our success rate of production is about >85% starting from cDNAs.
  • GenWay's IgY antibodies can be readily generated in 3 months simply based upon gene sequences or GenBank ID numbers identifying target proteins or cDNA templates. Our technology allows the generation of multiple antibodies against various sections of a gene product (expression domains), providing much greater diversity of antibody production
  • Polyclonal IgY antibodies have been shown to be suitable for standard immunoassays such as Western blot, ELISA, immunoprecipitation, immuno-staining of cell or tissue (Immunohistochemistry and Immunocytochemistry), etc. The quality of these assays using IgY antibodies is either comparable to or better than using conventional IgG antibodies. Of particular importance to some researchers is the capability of performing dual labeling experiments using both IgY and IgG primary antibodies. Secondary antibodies have no detectable cross-reactivity, permitting very clean interpretation of images.
  • IgY antibodies are particularly suitable for array, nano-bar, or microbead applications. In addition to Seppro® products and SepproServices, GenWay's antibodies have been successfully tested in the following two microarray systems by each company's scientists:
    • In the Luminex system, detection sensitivity reached 10 pg/ml;
    • On Ciphergen's ProteinChip, detection sensitivity reached 40 fg/ml.
  • IgY's strong avidity and stability are particularly useful for immunoaffinity separation and protein partitioning. GenWay's innovative product line of IgY microbeads, Seppro®, was specifically designed for immunoaffinity partitioning of proteins, which has proven to be useful for analysis of low-abundant proteins (LAP) and biomarker discovery. By eliminating the great majority of interfering proteins, Seppro® has been demonstrated to enhance 2-Dimensional Gel Electrophoresis (2DE) and Mass Spectrometry (MS) to detect those LAP previously inaccessible or masked by the highly abundant proteins (HAP). IgY-microbead possess the following unique features:
    • High specificity in capturing target proteins
    • Strong avidity in binding targets;
    • Great performance (>95% efficiency);
    • Flexibility for cross-species application;
    • Excellent reproducibility and recyclability.


For further information on the features and applications of IgY and IgG antibodies, as well as the related products such as secondary antibodies and antibody conjugates, please visit the pages:

Search GenWay's Catalog of Antibodies

GenWay offers extensive custom services in antibody development and applications. For more detailed information, please see the specific description pages in Custom Antibodies, and Immunoaffinity Separation.