title: Radioimmunodiffusion technique for determining diphtheria antitoxin.
abstract: A radioimmunodiffusion technique for detecting low levels of diphtheria antitoxin was developed. Diphtheria toxoid was labelled with 125I to facilitate detection of lines of precipitation by the use of X-ray film, the lower limit of detection being 0.001 unit per millilitre of diphtheria antitoxin.
mesh_terms: D004166:Diphtheria Antitoxin / Q000032:analysis*; D004168:Diphtheria Toxoid; D005069:Evaluation Studies as Topic; D006801:Humans; D005779:Immunodiffusion / Q000379:methods*; D007457:Iodine Radioisotopes
chemical_list: D004166:Diphtheria Antitoxin; D004168:Diphtheria Toxoid; D007457:Iodine Radioisotopes