The quality of the purification protocols was analyzed in polyacrylamide gel electrophoresis with sodium dodecyl sulphate (SDS-PAGE) at 8% in non-reducing conditions. IgY enrichment was assessed by slot dot assays, as follows: proteins samples obtained during IgY extraction were sequentially diluted 10-fold (10 mg to 10 24 mg) and transferred to nitrocellulose membrane by a vacuum apparatus (Bio-Dot SF; Bio-Rad, EUA). The presence of detectable chicken antibodies was verified by an rabbit anti-IgY antibody conjugated to peroxidase (Sigma) as secondary antibody, revealed by H 2 O 2 and DAB (Sigma).