title: Open-sandwich immunoassay for sensitive and broad-range detection of a shellfish toxin gonyautoxin.
abstract: At present, the analytical method for paralytic shellfish poisoning (PSP) toxins in shellfish is the mouse bioassay (MBA), which is an official method of the Association of Analytical Communities (AOAC [8]). However, the low sensitivity and concerns over the number of live animals required for testing have been cited as the major reason for seeking its replacement. In this report, we employed an open-sandwich immunoassay (OS-IA) to detect gonyautoxin (GTX2/3), a kind of PSP toxins. OS-IA, which utilizes the antigen-induced enhancement of antibody VH/VL interaction, can measure a small molecule antigen in a noncompetitive format. Hence it has a wider working range and shorter measurement time. We isolated anti-GTX2/3 antibody gene from a hybridoma GT-13A by screening a Fab-displaying phage library. Then the vectors for OS-IA were constructed, and examined for antigen concentration-dependency of the VH/VL interaction by OS-ELISA. As a result, in each case, signal intensity increases notably in a wide concentration range (0.1 to >1000 ng mL(-1)) of free GTX2/3, which was enough to cover its regulation value (80 μg 100 g(-1)) in many countries. So OS-IA will be widely applicable to detect PSP toxins in shellfish meats and in drinking water.
authors: Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors: Yuko
authors: Y
authors: Hara
authors: Jinhua
authors: J
authors: Dong
authors: Hiroshi
authors: H
authors: Ueda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000235:genetics / Q000276:immunology; D060766:Drinking Water / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D007135:Immunoglobulin Variable Region / Q000737:chemistry; D008969:Molecular Sequence Data; D019151:Peptide Library; D012530:Saxitoxin / Q000031:analogs & derivatives* / Q000032:analysis; D012758:Shellfish / Q000032:analysis*
chemical_list: D000906:Antibodies; D060766:Drinking Water; D007135:Immunoglobulin Variable Region; D019151:Peptide Library; D012530:Saxitoxin; C013007:gonyautoxins
keywords: Gonyautoxin; Hapten; Maltose binding protein; Open sandwich immunoassay; PSP toxins; Phage display