PROBLEM TO BE SOLVED: To provide a mass-production method of a yolk antibody present in yolk of an egg, in detail, to provide a method comprising hyperimmunizing a layer by using a virus, a microorganism, a protein or the like as an antigen, extracting a lipid from the yolk of the egg with an organic solvent to provide delipidated yolk residue, and readily purifying the yolk antibody in high purity and high recovery from the obtained yolk residue. SOLUTION: The solution of a water-soluble protein of the yolk containing 0.1-10 (v/v)% organic solvent and extracted from the delipidated yolk residue obtained by extracting the lipid component of the yolk with the organic solvent, with a salt solution is brought into contact with an anion exchanger column, and unadsorbed proteins are washed and removed by using a salt solution. The yolk antibody adsorbed on the column is eluted and collected from the resultant column by using a salt solution. COPYRIGHT: (C)2003,JPO
