title: Milk matrix effects on antibody binding analyzed by enzyme-linked immunosorbent assay and biolayer interferometry.
abstract: Biolayer interferometry (BLI) was employed to study the impact of the milk matrix on the binding of ricin to asialofetuin (ASF) and to antibodies. This optical sensing platform used ligands immobilized covalently or via biotin-streptavidin linkage, and the results were compared to those obtained by enzyme-linked immunosorbent assay (ELISA). In sandwich ELISA, the binding of ricin to ASF was dramatically decreased when galactose was present during the analyte or detection antibody binding step. Low concentrations of milk (1%, v/v) produced a similar reduction in ricin binding to ASF but not to a high-affinity monoclonal antibody (mAb), increasing the dissociation rate of ASF-ricin complexes up to 100-fold. The effect of milk on the binding of ricin to ASF was ascribable to dialyzable factors, and milk sugar can account for these effects. The use of high-affinity mAbs in ELISA effectively limits the milk matrix effect on ricin analysis.
authors.affiliation: Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, United States Department of Agriculture (USDA) Agricultural Research Service, 800 Buchanan Street, Albany, California 94710, United States.
authors.forename: David L
authors.initials: DL
authors.lastname: Brandon
authors.affiliation: Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, United States Department of Agriculture (USDA) Agricultural Research Service, 800 Buchanan Street, Albany, California 94710, United States.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Adams
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D001212:Asialoglycoproteins / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D060748:Fetuins / Q000378:metabolism*; D005690:Galactose / Q000494:pharmacology; D007785:Lactose / Q000494:pharmacology; D008892:Milk / Q000737:chemistry*; D012276:Ricin / Q000032:analysis* / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D001212:Asialoglycoproteins; D060748:Fetuins; C017029:asialofetuin; D012276:Ricin; D007785:Lactose; D005690:Galactose
keywords: Ricinus communis agglutinin; asialofetuin; biolayer interferometry; castor; milk; monoclonal antibody; ricin