What is the difference between the "IgY Fraction” and the “Affinity-Purified Antibody Fraction?"

IgY fraction refers to the total complement of antibodies circulating in the hen’s serum when an egg is produced. Affinity-purified antibody fraction refers to only those antibodies that bind to the antigen (or peptide) with high affinity. These affinity-purified antibodies typically correspond to 0.5%-2.0% of the total complement of circulating antibodies.