Egg yolk antibodies

Schade R, Behn I, Erhard M, Hlinak A, Staak C (eds.) (2001) Chicken egg yolk antibodies, production and application. Springer, Berlin Wild D (2005) The immunoassay handbook. Elsevier, Oxford... 

VanCoillie, E., J. DeBlock, and W. Reybroeck. 2004. Development of an indirect competitive ELISA for flumequine residues in raw milk using chicken egg yolk antibodies. J. Agric. Food Chem. 52 4975 4978. 

Hatta, H., Tsuda, K., Ozeki, M., Kim, M., Yamamoto, T., Otake, S., Hirasawa, M., Katz, J., Childers, N.K., and Michalek, S.M. 1997. Passive immunization against dental plaque formation in humans effect of a mouth rinse containing egg yolk antibodies (IgY) specific to Streptococcus mutans. Caries Res. 31, 268-274. 

The advantages of egg yolk antibodies with respect to the welfare of animals and to scientific and economic considerations are described in a recent review.50 Although antibodies issued from this source are mostly used in laboratories and for diagnostics, they must be extracted and purified from very complex mixtures. The presence of massive amount of insoluble material and lipids is the most important problem. The collected egg yolk must first be clarified and the lipid removed for a consistent chromatographic separation. Table 3 summarizes the most important characteristics of expression systems for antibody preparation with regards to the chromatographic separation. 

Schade, R., Hlinak, A., Marburger, A., Henklein, P., Morgenstern, R., Blankenstein, P., Gerl, M., Zott, A., Pfister, C., and Erhard, M. (1997). Advantages of using egg yolk antibodies in the life sciences. The results of five studies. Alternatives Lab. Anim. 25, 555-586. 

The concept of linking PCR and ELISA for ultrasensitive protein analysis soon sparked the imagination of laboratory scientists, and they developed a method that separates the concept of antibody-DNA linkage from hard-to-obtain protein chimeras. An easy way to establish the desired coupling was accessible with the streptavidin/biotin binding system The tetravalent protein STV, from Streptomyces avidii [19], derived, for example, as a recombinant core protein with optimized properties [20], or as its egg-yolk... 

Modern in vitro fermentation technologies can compete with in vivo production of antibodies regarding concentration and purity of the produced material. In fact, a number of more sophisticated methods of antibody expression have been developed in the last decade the most important are cell culture in protein-free media and the expression in the milk of transgenic animals, in transgenic plants, and in egg yolk. 

The extraction and purification of serum-derived immunoglobulin fraction in hen egg yolk by the combined treatment of the raw egg yolk with caprylic acid and ammonium sulfate has been reported.64 This simple two-step method proved to be rapid, reproducible, and suitable for batch processing of pooled egg yolks. The extraction procedure had no adverse effects on antibody titer. Caprylic acid is, in fact, a natural substance the concentration of autologous caprylic acid in serum is in the range of 40 ppm.65 No adverse effect of caprylic acid should be expected because of traces present in a pharmaceutical solution. Caprylic acid has a low toxicity for vertebrates but acts as a bacteriostatic agent. 

As detailed in Section III, initial raw materials for the production of antibodies are very different. Animal sera, transgenic milk, bovine colostrum, cell culture (hybridomas or other recombinant cells), ascites fluid, and egg yolk are the best known. Each raw material represents a potential carrier for adventitious agents. All of them can contain viruses. More specifically, animal sera used as source of antibodies, or as a cell culture medium supplement, can additionally carry mycoplasma and pyrogens depending on the method of collection. 

A number of additional strategies for signal amplification in ELISAs have been developed. One example is the use of secondary antibodies conjugated to biotin, a molecule that has very strong affinity (>10 1 mol ) for the egg yolk protein avidin. After application of the secondary antibodies and washing to remove unbound reagents, the substrate is flooded with an excess of enzyme-conjugated avidin. Not only is the interaction between avidin and biotin... 

Avidin (an egg yolk protein) exhibits an extremely strong afEnity (ca. lO L/mol) for biotin (vitamin H). This irreversible interaction can be utilized in the design of heterogeneous immunoassays with biotinylated. antigen-specific antibodies [68], [69]. Biotinylation can be performed without interfering with antibody function. The antibodies are applied in the usual manner in a competitive immunoassay (Fig. 8). In the last step, enzyme-labeled avidin is added in excess. Since there are four possibilities for the binding of avidin... 

Specific antibodies can be produced by injecting an antigen into an animal, such as chicken, and then extracting the antibodies from the egg yolk. These antibodies are called polyclonal antibodies, since several proteins can bind to the same antigen. In order to make antibodies that are specific for a single epitope of an antigen, called monoclonal antibodies, special cloning procedures are required. 

In response to the antigen, Dnp-bovine IgG, antihapten antibodies of all three classes appeared in the serum of a turtle 6 weeks after immunization. Only the 5.7 S class was found in an extract of the yolk of turtle eggs, which suggests that this class may have a selective advantage in its ability to pass through certain membranes (84). 

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