Application of the Indirect Fluorescent Antibody Method to the Diagnosis of Swine Toxoplasmosis

Abstract

A rabbit was immunized with γ-globulin purified from swine serum to produce a serum which showed a titer of 1: 128 in the precipitation test. Then γ-globulin was purified from this serum and labelled with FITC. Specificity was confirmed by using the labelled γ-globulin, free organisms of the RH strain, and antigen prepared from the intracerebral cyst of the Beverley strain. When the dye-testt titer was estimated by using Toxoplasma-positive swine serum, it was demonstrated that the Beverley strain gave rise to a stronger fluorescence. This labelled antibody was employed to compare the proposed method with the hemagglutination test. The results were almost the same between that method and this test. It is expected that the indirect fluorescent antibody method will be applicable to the diagnosis of toxoplasmosis more effectively if this method was standardized after solving some problems about it.