[Avian egg yolk antibodies. The egg laying capacity of hens following immunisation with antigens of different kind and origin and the efficiency of egg yolk antibodies in comparison to mammalian antibodies]

Based on some differences in physico-chemical andbiological activities between mammalian and avian antibodies, avian egg yolk antibodies are rather scarcely used in bio-medical research. These reservations are wide-spread but largely unjustified. In order to overcome such objections, detailed data concerning the practical use of egg yolk antibodies (IgY) are provided. An extraction method is presented based on ion exchange chromatography which yields 70-80% of highly purified antibodies. This method is quick and simple to perform. Furthermore, the substitution of mammalian IgG by avian IgY is demonstrated in two different test systems for quantitation of serum proteins relevant for diagnostic and medical basic research, respectively. The influence of adjuvant on the egg laying capacity is discussed, and the development of antibody titers is demonstrated. It is concluded that convincing arguments for substituting mammalian antibodies by IgY are required.