Effectivity of Alternative Adjuvants in Comparison to Freund's Complete Adjuvant.

In order to replace the use of mammals for the production of hyperimmune sera and to replace Freund"s complete adjuvant (FCA) with its undesirable side effects, the production and immunological features of IgY were investigated systematically. An important advantage of IgY is that large amounts can easily be extracted from the yolk of immunized laying hens. With special regard to animal welfare, several biocompatible adjuvants (ABM system, Gerbu adjuvant, TiterMax) were tested with FCA for their usage and effectiveness in the immunization of chickens. Under appropriate immunization schedules which strictly avoid intramuscular administration, IgY antibodies with very high titers and a strong binding capacity (avidity) comparable to rabbit hyperimmune sera can be obtained with minimal adjuvant side effects.

Effectivity of Different Methods for the Extraction and Purification of IgY.

Extraction of IgY from the egg yolk of immunized laying hens differs from the conventional way of antiserum preparation following blood sampling or exsanguination also with regard to the preparation technique. Six methods of IgY preparation were studied comparatively. As a result, the ammonium sulfate precipitation proved to be the most environmentally compatible and economical one. The advantage of this method becomes particularly obvious when the method is followed by affinity chromatography.

[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.