For the first time we found that cardiolipin was contained abundantly in Eschrichia coli, and we succeeded in isolating and purifying it as reported previously. With this E. coli cardiolipin a study was made on its reactivity
to Wassermann antibody reagin by OGATA'S box titration, and the following results were obtained. L The purity of cardiolipin prepared from E. coli has been found to be satisfactory on the thin-layer chromatogram, by its chemical analyses and by its infrared spectrum study. 2. The composition of fatty acids of E. coli cardiolipin differed considerably from that of beef heart cardiolipin in the point that unsaturated fatty acids occupied only less than 66% in the former. Therefore, in the preparation of antigen, EtOH containing 20% tetrahydrofuran was used,
which gave a clear solution, as E. coli cardiolipin did not dissolve completely in EtOH solution. 3. In the reaction made to take place with the serum from rabbit
immunized with beef heart cardiolipin, E. coli cardiolipin gave almost the same reactivity to that of beef heart cardiolipin. 4. The reactivity of E. coli cardiolipin to the sera of syphilitic patients was also paretically the same as that of OGATA'S antigen, while it did not show any reactivity against the sera of normal person.</p
