Monoclonal Antibody-Based Lateral Flow Assay for Detection of Botulinum Neurotoxin Type A

摘要

A rapid lateral flow assay was developed to detect botulinum neurotoxin type A (BoNT/A). The assay wasnbased on the sandwich format using monoclonal antibodies (MAbs) of two distinct specificities. One anti-nBoNT/A heavy chain MAb (150-3) was immobilized to a defined detection zone on a porous nitrocellulosenmembrane, while the other anti-BoNT/A heavy chain MAb (44.1) was conjugated to colloidal gold particles,nwhich served as a detection reagent. The BoNT/A-containing sample was added to the strip and allowed tonreact with MAb (44.1)-coated particles. The mixture was then passed along the porous membrane by capillarynaction past the MAb (150-3) in the detection zone, which binds the particles that had BoNT/A bound tontheir surface, giving a red color within this detection zone with intensity proportional to BoNT/A concentration.nIn the absence of BoNT/A, no immunogold was bound to the solid-phase antibody. With this method, 50nng/mL of BoNT/A were detected in less than 10 min. The assay sensitivity can be increased by silver enhancementnto 1 ng/mL. The developed BoNT/A assay also showed no cross-reaction to type B neurotoxinn(BoNT/B) and type E neurotoxin (BoNT/E).