Abstract
The complement fixation test is generally recognized as one of the most useful diag-nostic aids for the identification of toxoplasrnosis, especially for detection of the activestage of this disease. It is needless to say that the reliability of tone test depends chieflyupon the specificity of the antigen employed. Up to thc; present, earlier workers havereported many kinds of antigens such as those prepared from the rabbits or mice brains, chorioal[antoic membranes of the embryonated eggs, and the peritoneal exudate of miceor guinea-pigs, etc. Many criticisms have been made on the efficacy of these above notedantigens. From these observations, it is now suggested by many authors that the tissueculture may provide a more superior source of the C.F. antigen.In these circumstances, the present investigation was undertal<en to determine the use-fulness of the tissue culture supernatant antigen (TC-arrtigen), in comparison with the antigenfollowing WARREN and RUSS asmodified by SABIN (CAM-antigen). The materials andthe methods of making the tissue culture are quite similar to those described in theauthors preceding paper. The data obtained are briefly summarized as follows :l) In accordance with the multiplication of the organisms in tissue culture, C.F.antigen begins to appear in the tissue culture fluid and attains to the rnaxirrnum level.The days required for this coincides with, or may be l -2 days less than the elapsed tirnein which the maximunt multiplication of the organisms will occur (Fig. 1).2) The TC-antigen is only the supernatant of such tissue culture fluid, and is clearlyseparated from the organisms by centrifugation at 2, 000 r.p.m. for 20 minutes. Accordingly, compared with the other antigens, the TC-antigen is not very likely to contain any nonspecific components. It has a soluble nature and nonaruticomplementary activity and doesnot require further purifications.3) Rise of the antigenic Litre has intimate relationship with the multiplication of theorganisms. Wheru the multiplication stops within 2 - 3 x TO/ml, development of the anti-genie substaruce may cease in 8 units at the most, and require 4 -7 days for this. How-ever, it may rise to 16 -32 units in case more active multiplication should occur (Table 2).The yield of the antigenic substance rnay not have any intimate relation with the speciesof cells, - HeLa-, L- and dog lcidney cells, employed.4) The appearance of the antigenic substance may not be resulted from the destruc-Lion of the organisrn, but from the metabolie activities of the actively multiplied organisms(Tables 3, 4, 5 and 6).5) The TC-arntigen rnay not be inferior to the CAM-antigen irt many points of vievvsuch as the antigenic potenncy, specificity, and its usefulness in detecting the minor antibody(Taoles 11 and 12, and Fig. 3). Ultra centrifugation (100, ODD G for 120 minutes) and heattreatment do not reduce its
