Chickens were immunized with recombinant green fluorescent protein (GFP) emulsified in Freund’s adjuvant. After multiple injections, eggs were collected from the hens, IgY fractions were prepared from the yolks, and then affinity-purified antibodies were prepared using GFP conjugated to an agarose matrix. The final product is a mixture of both affinity-purified antibodies (30 µg/mL) and purified IgY (10 mg/mL), mixed with glycerol 1:1 (v/v) (to prevent freezing at -20°C), augmented with sodium azide and then filter-sterilized.