title: Colloidal gold-based immunochromatographic assay for detection of ricin.
abstract: A rapid immunochromatographic assay was developed to detect ricin. The assay was based on the sandwich format using monoclonal antibodies (Mabs) of two distinct specificities. One anti-ricin B chain Mab (1G7) was immobilized to a defined detection zone on a porous nitrocellulose membrane, while the other anti-ricin A chain Mab (5E11) was conjugated to colloidal gold particles which served as a detection reagent. The ricin-containing sample was added to the membrane and allowed to react with Mab (5E11)-coated particles. The mixture was then passed along the porous membrane by capillary action past the Mab (1G7) in the detection zone, which will bind the particles that had ricin bound to their surface, giving a red color within this detection zone with an intensity proportional to ricin concentration. In the absence of ricin, no immunogold was bound to the solid-phase antibody. With this method, 50 ng/ml of ricin was detected in less than 10 min. The assay sensitivity can be increased by silver enhancement to 100 pg/ml.
authors.affiliation: Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China.
authors.forename: Rong-Hwa
authors.initials: RH
authors.lastname: Shyu
authors.forename: Huey-Fen
authors.initials: HF
authors.lastname: Shyu
authors.forename: Hwan-Wun
authors.initials: HW
authors.lastname: Liu
authors.forename: Shiao-Shek
authors.initials: SS
authors.lastname: Tang
mesh_terms: D000911:Antibodies, Monoclonal; D002845:Chromatography / Q000379:methods*; D003102:Colloids; D006046:Gold; D007118:Immunoassay / Q000379:methods; D012276:Ricin / Q000032:analysis* / Q000276:immunology; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D003102:Colloids; D006046:Gold; D012276:Ricin