[A modified immunofluorescence test to demonstrate toxoplasma antibodies (author's transl)]

A modified test to demonstrate toxoplasma antibodies by immunofluorescence is described in detail. This test was used in more than 16 000 cases. The antibody content of a patient's serum is assessed from a single dilution of 1:4 by two criteria: 1. The number of toxoplasms in the assay is kept constant. The percentage of antibody loaded cells varies with the concentration of antibodies in the patient's serum. 2. The intensity of fluorescence is correlated to the antibody content of the serum and the latter can be determined by means of standard sera. The results of this method are expressed in degrees of brightness. We compared three different methods and found an identical behaviour of the FATOX III and the Sabin-Feldman test. Between the complement-fixation test and the FATOX III there is the same relation as between JFT and SFT. This is shown in tables presenting the results for 1621 sera. The method is described in detail.