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