Development and application of an enzyme immunoassay based on a monoclonal antibody against gonyautoxin components of paralytic shellfish poisoning toxins.
With a gonyautoxin 2/3 (GTX2/3)-specific monoclonal antibody (designated GT-13A) and a saxitoxin-horseradish peroxidase conjugate (STX-HRP), a direct competitive enzyme immunoassay (GTX-EIA) was established and its sensitivity to various toxin components was investigated. The concentrations resulting in 50% inhibition of the binding of STX-HRP to the solid-phase GT-13A antibody for GTX2/3, decarbamoyl-GTX2/3 (dc-GTX2/3), N-sulfocarbamoyl-GTX2/3 (C1/2), GTX1/4, STX, and neosaxitoxin (neoSTX) in GTX-EIA were found to be 0.28, 0.41, 0.52, 3.46, 4.06, and 89.37 ng/ml, respectively. When the minimum detection limit was assumed to be at a toxin concentration causing 30% inhibition of the binding of STX-HRP to the solid-phase GT-13A antibody, the detection limits for GTX2/3, dc-GTX2/3, C1/2, GTX1/4, STX, and neoSTX were found to be 0.15, 0.18, 0.19, 1.09, 1.50, and 22.93 ng/ml, respectively. These results indicate that all of the GTX components examined and STX are detectable at concentrations lower than the regulatory limit of 80 microg/100 g of shellfish tissue, even when a minimum dilution factor of 100 is applied to tissue extracts with the extraction procedure of the Association of Official Analytical Chemists. Therefore, GTX-EIA is thought to be a useful qualitative screening method for GTX components and STX in the mass monitoring of toxin-contaminated shellfish.
Kawatsu
Kentaro
K
Division of Food Microbiology, Osaka Prefectural Institute of Public Health, Japan. kawatu@iph.pref.osaka.jp
Hamano
Yonekazu
Y
Sugiyama
Akira
A
Hashizume
Kiyoshi
K
Noguchi
Tamao
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D008387:Marine Toxins; D009498:Neurotoxins / Q000276:immunology*; D017747:Seafood; D012680:Sensitivity and Specificity; D012758:Shellfish / Q000382:microbiology*
D000911:Antibodies, Monoclonal; D008387:Marine Toxins; D009498:Neurotoxins