Chickenswereimmunizedwithpurifiedß-Galactosidase(lacZ)proteinemulsifiedinFreund’sadjuvants.Aftermultipleinjections,eggswerecollectedfromthehens,IgYfractionswerepreparedfromtheyolks,andthenaffinity-purifiedantibodieswerepreparedusingß-Galactosidaseconjugatedtoanagarosematrix.Thefinalproductisamixtureofbothaffinity-purifiedantibodies(25µg/ml)andpurifiedIgY(10mg/ml),andisfilter-sterilized.