Separation of Immunoglobulin G from Cheddar Cheese Whey by Avidin‐Biotinylated IgY Chromatography

High-purity immunoglobulins (Ig), which may be useful for immunologic supplementation of food products, were isolated from Cheddar cheese whey in a one-step process using avidin-biotinylated yolk immunoglobulin (IgY) column chromatography. Yolk antibodies specific to bovine IgG (IgY IgG ) were biotinylated with biotinyl amido-hexanoic acid-N-hydroxy-sulfo-succinimide ester without any notable effect on antigen-binding activity, and coupled to immobilized avidin columns. The resulting avidin-biotinylated IgY IgG columns, with binding capacity of 50-55% (w/w percent ratio of IgG to immobilized IgY IgG ), were used for specific binding of IgG from cheese whey. Elution with a commercially available eluent (Actisep) or 0.1M glycine-HCl buffer at pH 2.8 yielded IgG with purity of 99% by radial immunodiffusion.