title: Development of sensitive colorimetric capture elisas for Clostridium botulinum neurotoxin serotypes A and B.
abstract: Sensitive and specific enzyme-linked immunosorbent assays were developed to detect Clostridium botulinum neurotoxin serotypes A (BoNT A) and B (BoNT B) in assay buffer and human serum. The assay is based upon affinity-purified horse polyclonal antibodies directed against the approximately 50 kDa C-fragments of each toxin. Standard curves were linear over the range of 0.1-10 ng mL. Detection was possible at 0.2 ng mL (20 pg/well) and accurate quantitation at 0.5 ng/mL (50 pg well) in assay buffer and 10% human serum. Variations between triplicates was typically 5-10%. Less than 1% cross reactivity occurred between other serotypes when each assay was performed against serotypes A, B and E. When tested against toxins complexed to their associated nontoxic proteins, interference was absent (BoNT B) or < 25% (BoNT A). These assays demonstrate sensitivity close to that of the mouse bioassay without the use of animals and in a much simpler format than other reported assays of similar sensitivity.
authors.affiliation: Aeronautical and Maritime Research Laboratory, Defence Science and Technology Organization, Maribyrnong, Vic., Australia.
authors.forename: M
authors.initials: M
authors.lastname: Szílagyi
authors.forename: V R
authors.initials: VR
authors.lastname: Rivera
authors.forename: D
authors.initials: D
authors.lastname: Neal
authors.forename: G A
authors.initials: GA
authors.lastname: Merrill
authors.forename: M A
authors.initials: MA
authors.lastname: Poli
mesh_terms: D000818:Animals; D001681:Biological Assay; D001710:Biotin / Q000737:chemistry; D001905:Botulinum Toxins / Q000032:analysis*; D019274:Botulinum Toxins, Type A / Q000032:analysis*; D002846:Chromatography, Affinity; D003124:Colorimetry; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D051379:Mice; D009498:Neurotoxins / Q000032:analysis*
chemical_list: D009498:Neurotoxins; C096323:rimabotulinumtoxinB; D001710:Biotin; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A