Dot-immunobinding assay in the serodiagnosis of human hydatid disease

A rapid and convenient procedure for the indirect serological detection of anti-Echinococcus antibodies in human hydatid disease is described. Sheep hydatid cyst fluid was spotted on nitrocellulose membranes. All remaining unbound sites on the membrane were blocked with polyxyethylene sorbitan monolaurate (Tween 20). The immobilized antigens were then reacted first with human serum to be diagnosed followed by reaction with horse anti-human IgG conjugated with peroxidase or protein A conjugated with peroxidase. The conjugated enzyme was then detected by the formation of the blue-brown precipitate which permanently stained the nitrocellulose membrane when the peroxidase reacted with benzidine-HCl and hydrogen peroxide. The results indicate that the dot-immunobinding assay is sensitive, specific, economical, fast and safe for serodiagnosis of hydatid disease. This is the first report of diagnosing human hydatid disease by the dot-immunobinding assay.