Quantitative study of immune horse serum antibody a gainst Clostridium oedematiens by means of precipitation on paper or paper-fixed antigen

Reaction of flocculation between the antitoxin ofCl,oedematiens and the corresponding immune horse serum was studied with the aid of precipitation on paper. When toxin and immune serum were placed on the same place on the paper, a flocculate appears, which unlike all the rest of the proteins is not washed off the paper by the veronal buffer. The fiocculate is precipitated at the zone of considerabic surplus of antitoxin. The quantity of precipitate is increased in proportion to the quantity of the added antigen up to the time when the whole quantity of the antigen is precipitated. Then the precipitate begins to dissolve in the surplus of the antigen. Data which were obtained by the method of precipitation on paper correspond to the results of determination of the quantity of the antibodies in the same serum with the aid of the antigen fixed on paper through diazoconnection and the residual haloidalkylate. This points to the possibillity of replacement of the biological method of determination of the antigens ofCl.oedematiens by the immunochemical method.