[Simple method for obtaining Toxocara canis antigen for the indirect immunofluorescence technic]

A simple method for the preparation of Toxocara canis antigen for the indirect immunofluorescent test is described: Embryonated Toxocara eggs are treated for 12 hours at room temperature with a 1:1 mixture of 2% NaHO and sodium hypochlorite (NaClO) solution with a concentration of 2% free chlorine in order to remove the outer layers of the egg shells. The larvae which are still enclosed in the lipid membrane are freed by mild ultrasonic treatment. Thereafter, the suspension of larvae is washed and purified in a modified Baermann apparatus. In this way large numbers of larvae in pure suspension were gained and used for the production of frozen sections for the indirect immunofluorescent test. Rabbits and mice experimentally infected with embryonated Toxocara canis eggs showed a positive serological reaction (titers between 1/10 to 1/320) in this test with Toxocara larvae as antigen, while in uninfected control animals no antibodies could be detected. The larval antigen exhibited only a weak cross reaction with sera of animals infected with Ascaris suum eggs.