Chicken Antibodies

Chicken antibodies offer many advantages to traditional mammalian antibodies when used for the detection of mammalian antigens. Due to the evolutionary difference between chickens, IgY will react with more epitopes on a mammalian antigen, which will give an amplification of the signal.

The chicken is an ideal choice as a non-mammalian host species when using mammalian or human protein antigens. Since chickens are not mammals, they generally produce high avidity antibodies to mammalian antigens, especially those highly conserved. The protein structure of mammalian proteins is similar between different species.

Some of the other advantages of IgY antibodies in the chicken are that: The process of collecting the antibodies is much less invasive compared to other host species as the antibodies are found within the yolk of the egg. Approximately 2-3g of antibody types can be collected from one chicken in one month. IgY does not bind to protein A/G. IgY antibodies do not recognize mammalian Fc receptors. Generally, a specific antibody response can be seen much quicker than in mammalian host species. Eggs can be stored at 4ºC for at least six months without a reduction in the quality.

IgY is genetically and structurally different from its mammalian counterpart IgG. Like IgG, IgY has two heavy chains and two light chains shaped in the characteristic Y-shape with an antigen valency of 2. IgG and IgY are both major immunoglobulins that provide defense against infectious agents and appear in the bloodstream at high concentrations following exposure to an antigen. Functionally, they play similar biological roles.

IgY has a higher molecular weight due to an extra heavy chain constant domain. IgY also has a unique glycosylation pattern. In chickens, IgY is actively transported to the egg yolk where the IgY concentration is ultimately higher than in blood. However, there is little or no immunological cross-reactivity between IgY and mammalian IgG.

IgY is a highly specific polyclonal antibody suitable for a range of immunoassays and applications. Using chicken antibodies in immunological assays may improve their diagnostic product's selectivity, sensitivity, and reliability. That is largely attributed to the inherent low degree of interference and good stability of IgY.

Chickens are domesticated birds that genetically differ significantly from humans and other mammals. Hence, chickens may raise a stronger immune response against human antigens than, for instance, rabbit anti-llama HRP, mice, or goats. Chickens often recognize a larger part of the antigen as foreign and may be used to obtain antibodies against human antigens in cases where antibody production in mammals has failed.

IgY does not bind to mammalian Fc receptors. Both complement activation and Fc-receptor interactions cause platelet activation, which is commonly seen in assays using mammalian IgG antibodies. That is not the case with chicken antibodies, making IgY suitable for studies of platelet activation by flow cytometry.