Preparation of lipid-free protein extracts of egg yolk.

1-Butanol extraction of chicken egg yolk homogenates containing 1 M NaCl yields lipid-free aqueous solutions of egg yolk proteins. These solutions, after dialysis, can be applied to a variety of chromatographic media without clogging. Although some proteins are denatured by this procedure, most of the water-soluble proteins remain in solution, including biotin-binding protein and riboflavin-binding protein.