[Purification and clinical application of egg yolk immunoglobulins]

IgY antibodies, also called egg yolk immunoglobulins, are the only immunoglobulins in egg yolk and transferred in the female from serum to egg yolk to confer passive immunity to embryos and neonates. Using hens instead of mammals as the immunization host brings a number of advantages: Eggs are cheap and readily available; antibody levels in yolks are high; IgY isolation is fast and simple; and what is more; IgY neither binds the rheumatoid factor nor reacts to the mammalian complement factor. All these differences make IgY technology more widely applicable, such as in the production of polyclonal antibodies against various antigens, immunodiagnostics and immunotherapy, and many medical areas in both animals and human. IgY also has a good prospect in human immunocontraception.