Polyclonal IgY antibodies from chicken egg yolk--an alternative to the production of mammalian IgG type antibodies in rabbits

By Schade, R. - Pfister, C. - Halatsch, R. - Henklein, P.

Based on a physiological process, antibodies are concentrated in the yolk of chicken eggs, and can be used as a convenient source of polyclonal antibodies. Hens were immunised with a BSA-cholecystokinin octapeptide conjugate (CCK-8) to obtain antibodies against CCK-8. A simple method is described for extracting the antibodies from egg yolk, which can then successfully be used in immunocytochemical studies. Using these antibodies, CCK-like immunoreactivity was found in brain sections of rats, both by fluorescein isothiocyanate and peroxidase staining. The specificities of these antibodies were different from those of rabbit antibodies against the C-terminal part of CCK-8. The applicability of egg yolk antibodies in immunological investigations is reviewed and discussed in detail. The properties of avian egg yolk antibodies are compared with those of polyclonal antibodies obtained from mammals (e.g. the rabbit). The more general use of avian antibodies is emphasised as a real alternative, taking into consideration the reduction in animal suffering involved in comparison with the classical immunisation techniques used on rabbits.