有機溶媒耐性マウスモノクローナル抗オカダ酸抗体を用いた下痢性貝毒(オカダ酸群)の酵素免疫測定法  [in Japanese] An ELISA for Okadaic Acid and Its Analogs among the Diarrhetic Shellfish Toxins Using Mouse Monoclonal Anti-Okadaic Acid Antibodies which Are Resistant to Organic Solvents  [in Japanese]

A specific and sensitive enzyme-linked immunosorbent assay using immobilized mouse monoclonal antibodies to okadaic acid (OA), OA423-3 and OA958-2,which are resistant to organic solvents, has been established to determine OA and its analogs (OAs). OA423-3 (IgG_<1-x>), which bound only OA in 10% (v/v) aqueous methanol, is useful to determine OA selectively. The quantitative determination range of OA was 70 pg-6.0 ng/ml, and the coefficient of variation (cv) within six independent analyses was 15.4% at the OA concentration of 0.52 ng/ml. Besides, OA958-2 (IgG_<1-x>), which equally bound OA, dinophysistoxin-1 (DTX_1) and 7-O-palmitoyl-dinophysistoxin-1 (Pal-DTX_1) in methanol, is successful in determing total OAs. The quantitative determination range of each toxin was 4.1 ng-2.2 μg/ml for OA, 4.9 ng-2.25 μg/ml for DTX_1 and 11.0 ng-1.15 μg/ml for Pal-DTX_1,respectively. The cv values were 12.9-17.5% at the toxin concentration of about 100 ng/ml. As to determine each of OAs, the mixture of OAs was first partitioned between n-hexane and 60% (v/v) aqueous methanol. Total amount of OA and DTX_1 in 60% (v/v) aqueous methanol and the amount of Pal-DTX_1 in n-hexane were determined using OA958-2 in methanol. And the amount of OA in 60% (v/v) aqueous methanol was determined using OA423-3 in 10% (v/v) aqueous methanol. The amount of DTX_1 was calculated by subtracting the amount of OA from the total amount of OA and DTX_1. The determination of the mixture of 500 ng each of OAs resulted in 1591 ng as OA for total OAs, 500 ng for OA, 474 ng for DTX_1 and 519 ng for Pal-DTX_1,respectively. The recovery test using nontoxic scallops and blue mussels fortified with 1.0,2.0 and 10 μg of OA, DTX_1 or Pal-DTX_1/g of hepatopancreases resulted in 100.8-107.8% of recovery rates.