Custom Chicken IgY Antibody Production
Creative Biolabs together with partners who are leading scientists in monoclonal chicken IgY antibody field offers the most recognized custom monoclonal chicken IgY antibody production services. Chicken IgY antibodies are avian equivalents of mammalian IgG antibodies.Compared to mammalian IgG antibodies, chicken IgY antibodies have higher avidity, less cross-reactivity and higher specificity, rendering chicken IgY antibodies more valuable in laboratory experiments and diagnostic assays.
Our IgY Monoclonal production service is based on our unparalleled expertise in phage display antibody library construction and screening. Starting with antigen design andchicken immunization, genes [i.e., cDNA fragments] encoding IgYantibody repertoire are PCR amplified and used for phage library construction; after that the library is screened for positive antibody binders. Antibodies are then expressed in E. coli, and monoclonal antibodies are characterized and delivered to the client. We are also able to produce monoclonal scFv or Fab types of IgY antibody after phage display library screening. Furthermore, we are able to produce chimericIgY by transferring the scFv regions of the IgY monoclonal antibodies into a human IgG expression vector and manufacture the chimeric antibody in CHO cells.
We are experienced in making phage-display chicken single-chain antibody fragment libraries that can provide useful diagnostic and researchreagents by bio-panning. Using avian immunoglobulin genes simplifies the construction of such repertoires since far fewerprimer sets are required to access the avian antibody repertoire than is the case with mice or humans. Librariesconstructed using mRNA from an immune source are enriched in affinity-matured sequences and consequentlyneed not be as large as ‘‘universal’’ non-immune repertoires to have a reasonable probability of yielding highaffinitybinders. Antibody repertoires focused on a number of defined targets can be constructed using lymphocytemRNA from chickens immunized with a mixture of several different antigens. Immune responses to each of the individual antigens can be determined by extracting egg-yolk IgYand testing for antigen-specific antibodies in ELISA. The chicken splenocytesare then recovered, RNA is extracted, and after reverse transcription, the immunoglobulin VH and VL regions are amplified by PCR andjoined via a single glycyl residue for surface expression on a collection of filamentous bacteriophages. Theresulting display library is to be screened by panning to isolate binders. The immunized chickens may not respond equally well to all the different antigens, nor is it possible to derive antibody fragmentsagainst all the targets.
In constructing recombinant antibody libraries,the chicken also offers a significant technical advantage in that only one set of primers for each VH and VL gene segment is required to access its immunoglobulin repertoire.This is because its immunoglobulin diversity is generated by means of gene conversion that uses non-functional pseudogenes located upstream of the functional VH or VL gene, a process that does not affect the N- or C-terminal sequences of the rearranged gene segments.
Chicken antibody libraries can be constructed using mRNA from either naïve or immunebirds. A ‘‘naive’’antibody fragment library relies largely on the primary V-gene repertoire for its diversity and therefore includes a broad spectrum of antibody specificities. Although potentially a ‘‘universal’’ source of antibodies, such a library has to be exceedingly large to have a reasonable probability of yielding high-affinity binders.In contrast, useable libraries from an immune source can be considerably smaller. This is because the amplified V-region genes will already have undergone affinity-maturation and clonal selection in vivo. A disadvantage of using immune repertoires, however, is that it is necessary to elicit a response to each antigen against which antibodies are required. Rather than using a separate bird for each target, ‘‘oligospecific’’ libraries may beconstructed by simultaneously immunizing with several different antigens.
Creative Diagnostics provides the most cost-effective custom chicken IgY antibody production services in the industry. Chicken IgY antibodies are avian equivalents of mammalian IgG antibodies. Chicken antibodies are produced by immunization of laying hens and subsequently purification of IgY from the egg yolk. As described more than 100 years ago, avian maternal antibodies are transferred from serum to egg yolk to confer passive immunity to embryos and neonates. The IgY concentration in the yolk is slightly higher than the IgY concentration in the chicken serum. Typically, each egg contains about 50-100mg of total IgY [comparable to IgG in 10mL rabbit serum], and the antigen-specific antibody is about 1-10% of the total.
Our staff scientists have in the past 5 years produced IgY antibodies targeting over 1500 antigens, the largest number for a single company in the world. Our standard polyclonal IgY production service involves two chickens and 16 eggs. Our proprietary IgY purification system allows production of ultra-pure total IgY at low cost. We also conduct antigen affinity purification using purified total IgY to isolate the antigen-specific antibodies for immuno-labeling or other purposes. Our antigen affinity purification protocol employs affinity chromatography, ion exchange and gel filtration columns.
o Advantages of Chicken IgY Antibodies
Higher avidity: most mammalian proteins exhibit enhanced immunogenicity in chickens than in mammals due to phylogenetic distance, and thus raise antibodies of higher avidity; this also makes production of antibodies against conserved mammalian proteins more successful in chicken than in mammals.
Higher specificity: compared with mammalian IgG, chicken IgY has less cross reactivity with mammalian proteins other than the immunogen;
Lower background: IgY and IgG are structurally different in the Fc region; IgY does not bind to IgG Fc receptors and causes less false positive staining.
High yield: very low quantities of antigen are required to obtain high and long-lasting IgY titer in the egg yolk; chickens lay eggs regularly, providing a continual source of IgY antibody