Rapid enzyme immunoassay of chicken egg yolk IgG

A simple and rapid enzyme immunoassay for specific antibodies in chicken egg yolk is described. As a model system, the levels of anti-Salmonella IgG in the yolk of eggs obtained from various produce retailers were compared. Polyester cloth coated with Salmonella typhimurium lipopolysaccharide was used to capture specific egg yolk antibodies, which were then detected using an anti-chicken IgG-peroxidase conjugate. This assay, requiring less than 30 min to complete, revealed considerable differences in the relative levels of anti-Salmonella IgG in the egg yolks. Anti-Salmonella IgG levels were generally lower in eggs obtained from large produce retailers than in eggs obtained from a small local farm. This assay may provide a rapid and economical means of monitoring the levels of Salmonella contamination in chicken rearing facilities.