[Detection and titration of anti-tetanus antibodies by passive hemagglutination].

Human red cells O Rh + are coated with purified tetanus toxoid, by means of chromic chloride as coupling agent. With this reagent and by passive haemagglutination technique, antitetanus antibodies can be automatically screened and titrated in blood donnors plasmas, on Groupamatic equipments. Comparative results of three techniques: counter immunoelectrophoresis; manual passive haemagglutination; automatic passive haemagglutination are given, 4, 92 percent among the 1.219 tested blood donnors plasmas have an antibody greater than or equal to 5 U.I., 16, 24 percent have a titre between 1 and 5 U.I.