Read below to learn how Aves Labs' PrecipHen® Immunoprecipitation Reagent can help overcome a common disadvantage of using Protein A- and Protein G-immunoreagents for immunoprecipitation. Our PrecipHen® is made from goat anti-chicken IgY antibodies covalently attached to agarose beads. It is designed for use with chicken antibodies in immunoprecipitation (IP), chromatin immunoprecipitation (ChIP), and protein purification applications.
Needless to say, we are in the business of providing high-quality chicken IgY because we think it is well worth your consideration. Here's our list of pros and cons when it comes to the nature and use of chicken IgY as a research tool.
Advantages
We count six major advantages of using chicken IgY as a research tool:
- Since birds are so far removed evolutionarily from mammals, they tend to respond vigorously to most mammalian proteins. This is particularly important for production of antibodies against highly-conserved mammalian gene products, where there are only a few differences in the amino acid sequence of the target protein and the hosts’ homolog.
- It is much simpler to perform double immunostaining studies with mouse or rabbit antibodies because secondary anti-chicken IgY doesn’t cross-react with mammalian IgG.
- The price of chicken antibodies is considerably cheaper if you compare equivalent degrees of purification. The price, for example, of about 1.5 grams of protein A-purified rabbit IgY is about twice that of 1.5 grams of purified chicken IgY.
- Since chicken IgY lacks an “Fc domain,” they don’t bind “rheumatoid factors” found in the serum of animals (or humans) with chronic inflammatory diseases. Therefore, in research applications using serum from such animals (or humans), the rate of “false positives” due to rheumatoid factors is considerably lower.
- In applications that require binding of antibody to solid surfaces (e.g., ELISA, antibody microarray, etc.), one can absorb about twice as much chicken IgY to a glass or plastic surface than rabbit IgG. This is presumably due to the higher carbohydrate content in chicken IgY (about 3% carbohydrate as compared to about 1% in rabbit IgG).
- The higher content of carbohydrate allows a higher degree of enzyme- or hapten-conjugation away from the antigen-binding regions of the antibody. For example, one can easily conjugate 15-20 biotins per chicken IgY using hydrazide carbohydrate chemistry, as compared to 7-10 per rabbit IgG.
Disadvantages
There are two potential downsides of chicken IgY, and some minor inconveniences:
- Labs that use birds as a primary experimental animal may find chicken IgY difficult to use, in much the same way that mouse labs have difficultly using mouse antibodies: secondary antibodies cross-react with endogenous antibodies in the experimental animals. For this reason, we recommend that chicken labs use other host animals for their antibody production.
- In applications that require Fab fragments, chicken IgY may be less cost-effective than rabbit IgG. It is much more expensive to produce Fab fragments from chicken IgY molecules than from rabbit IgG’s because chicken IgY lacks the sequence to which protein A binds, necessitating the use of anti-chicken IgY-stem antibodies to separate the IgY-stems from the Fab fragments.
- Since chicken IgY does not have sequences that bind proteins A or G, labs that tend to use protein A- or protein G-immunoreagents for immunoprecipitation would need to use an alternative. We provide our PrecipHen® product, an affinity-purified goat anti-chicken IgY coupled to agarose, to help customers easily overcome this issue.
- Presumably due to their high carbohydrate content, PVDF and other nylon-based membranes bind chicken antibodies non-specifically. Therefore, labs that use PVDF membranes for their Western Blots would need to use pure nitrocellulose membranes instead of PVDF. For most purposes, nitrocellulose membranes substitute beautifully for other, nylon-based membranes.