Development of a displacement immunoassay by exploiting cross-reactivity of a monoclonal antibody.
An enzyme-linked immunosorbent assay-based displacement assay was developed for the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Advantage was taken of the cross-reactivity of a monoclonal anti-2,4-D antibody toward 2-methyl-4-chlorophenoxyacetic acid (MCPA). MCPA was conjugated with bovine serum albumin (BSA), immobilized on the surface of a microtiter plate, and saturated with the anti-2,4-D antibody. Due to the low affinity of the antibody toward MCPA (cross-reactivity of approximately 30%), the addition of 2,4-D resulted in a displacement of the antibody. Remaining antibodies were subsequently detected using a peroxidase-labeled goat anti-mouse antibody. The detection limit was as low as 0.1 microgram/liter for 2,4-D, which complies with the European Union Drinking Water Directives. When 2,4-D-BSA was used instead of MCPA-BSA conjugates, no significant displacement of bound antibody was observed.
Gerdes
M
M
Institut für Chemo- und Biosensorik, Münster, Germany.
Meusel
M
M
Spener
F
F
D015084:2,4-Dichlorophenoxyacetic Acid / Q000032:analysis* / Q000276:immunology; D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000302:isolation & purification; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006241:Haptens / Q000032:analysis / Q000276:immunology; D007210:Indoleacetic Acids / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry
D000911:Antibodies, Monoclonal; D006241:Haptens; D007210:Indoleacetic Acids; D015084:2,4-Dichlorophenoxyacetic Acid; D012710:Serum Albumin, Bovine; C030737:indoleacetic acid; D008456:2-Methyl-4-chlorophenoxyacetic Acid