title: Toxoid flocculation assay by laser light-scattering.
abstract: Internationally accepted designations of antigen content for toxoid vaccines are provided by the WHO in Lf (limes flocculationis) units, based on the formation of antigen-antibody complexes. The current assay method for Lf determination involves observation of the complexes by eye, making the development of a more objective system highly desirable. Here we report a novel detection system using a laser light-scattering platelet aggregometer. The system was highly reproducible and more objective than the current method. Only three sets of duplicate data were sufficient for statistically significant determination of toxoid Lf by parabolic regression.
authors.affiliation: Department of Bacterial Pathogenesis and Infection Control, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama-shi, Tokyo 208-0011 Japan. miwaki@nih.go.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Iwaki
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Horiuchi
authors.forename: Takako
authors.initials: T
authors.lastname: Komiya
authors.forename: Tadashi
authors.initials: T
authors.lastname: Fukuda
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Arakawa
authors.forename: Motohide
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D000936:Antigen-Antibody Complex / Q000032:analysis*; D004166:Diphtheria Antitoxin / Q000276:immunology; D004168:Diphtheria Toxoid / Q000032:analysis / Q000276:immunology; D005428:Flocculation Tests / Q000379:methods; D007834:Lasers; D008027:Light; D010316:Particle Size; D012044:Regression Analysis; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D013743:Tetanus Antitoxin / Q000276:immunology; D013745:Tetanus Toxoid / Q000032:analysis / Q000276:immunology; D014121:Toxoids / Q000032:analysis* / Q000276:immunology
chemical_list: D000936:Antigen-Antibody Complex; D004166:Diphtheria Antitoxin; D004168:Diphtheria Toxoid; D013743:Tetanus Antitoxin; D013745:Tetanus Toxoid; D014121:Toxoids