title: A novel method to detect Listeria monocytogenes via superparamagnetic lateral flow immunoassay.
abstract: A novel strip test system combining immunomagnetic separation with lateral flow immunoassay (LFIA) was established for the accurate detection of Listeria monocytogenes. In this system, a pair of matched monoclonal antibodies was used to construct a sandwich immunoassay, in which superparamagnetic particles were coupled with one of the antibodies as a labeled antibody to capture the target bacteria, while the other antibody was immobilized on the detection zone. After a 20-min reaction, the strips were analyzed by a novel instrument which could detect the magnetic signal of the immunocomplex in a magnetic field. Sensitivity evaluation showed that the limit of detection (LOD) of the superparamagnetic LFIA system for L. monocytogenes was 10(4) CFU/mL, which was at least one log lower than conventional LFIA. No cross-reaction was observed when Salmonella, Escherichia coli O157:H7, or three types of harmless Listeria strains were tested. Further evaluation with actual food samples indicated that the superparamagnetic LFIA system showed 100 % concordance with real-time PCR. Therefore, this novel superparamagnetic LFIA system could be used as a rapid, sensitive, and specific method for the detection of L. monocytogenes.
authors.affiliation: Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou, Guangdong, 510632, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.forename: Yiming
authors.initials: Y
authors.lastname: Wen
authors.forename: Fang
authors.initials: F
authors.lastname: Zhao
authors.forename: Junjian
authors.initials: J
authors.lastname: Xiang
authors.forename: Lan
authors.initials: L
authors.lastname: Ma
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D000911:Antibodies, Monoclonal; D003429:Cross Reactions; D004867:Equipment Design; D019453:Escherichia coli O157 / Q000276:immunology; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology / Q000379:methods*; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D018189:Immunomagnetic Separation / Q000379:methods; D057230:Limit of Detection; D008089:Listeria monocytogenes / Q000235:genetics / Q000276:immunology; D060888:Real-Time Polymerase Chain Reaction; D012475:Salmonella / Q000276:immunology; D012680:Sensitivity and Specificity
chemical_list: D055910:Antibodies, Immobilized; D000911:Antibodies, Monoclonal