Isolation of IgY from Chicken Eggs.

Because IgY does not interact with either Protein A or Protein G, more traditional methods must be used for its isolation. To isolate chicken IgY from the yolk of chicken eggs, the yolks and the whites must be separated much in the way a cook does. Minimizing the egg white proteins is an important part of this process. Although eggs can be accumulated for short periods of time, IgY must be isolated from the yolk within 2-3 wk to avoid fouling of the material. In the first section of this protocol, sodium sulfate is used to precipitate protein fractions differentially from the chicken egg yolk. The second section describes an alternative differential precipitation technique that uses Polyethylene Glycol 6000 instead of sodium sulfate.