Domoic Acid (ASP) (AOAC Method 2006.02), ELISA 96 tests
Immunoassay for the quantitative and sensitive detection of Domoic Acid (ASP); AOAC Method 2006.02. Domoic Acid is one of the toxins associated with amnesiac shellfish poisoning (ASP). This test is suitable for the quantitative and/or qualitative detection of Domoic Acid in water samples as well as shellfish samples. For shellfish samples a sample preparation is required. Samples requiring regulatory action should be confirmed by HPLC, GC/MS, or other conventional methods. The assay is in a direct competition format, where free Domoic Acid (DA) in the sample competes with DA-conjugated protein coated on plastic wells for binding to anti-DA antibodies free in the solution (Fig. 2). The polyclonal ovine anti-DA antibodies are conjugated to horseradish peroxidase (HRP). Sample diluted in buffer is incubated in the wells with the anti-DA-antibody-HRP conjugate. After washing, the amount of conjugate remaining bound to the well is measured by incubation with a substrate that gives a blue product upon reaction with the HRP enzyme. Addition of acid stops the reaction and changes the product colour from blue to yellow. The colour intensity is measured spectrophotometrically on a plate-reader at 450 nm, and is inversely proportional to the concentration of DA in the sample solution. The assay is calibrated using dilutions of a DA calibration solution supplied with the kit. The calibrated range of the assay (I20 – I80) is approximately 10 to 300 pg/mL of DA. The ASP ELISA is offered in a 8x12 strip well format. The ASP ELISA kit can be used in 2 separate rounds to analyze 12 samples each time, or the full plate can be used to analyze 36 samples in one round of analysis. The working range for ASP toxins in shellfish is 0.01mg/kg up to at least 250 mg/kg.