Production and Characterization of Antibody Against PR Toxin.

Antibody against PR toxin was produced after immunizing rabbits with an immunogen prepared by conjugation of PR toxin to bovine serum albumin by a reductive alkylation method. A competitive radioimmunoassay (RIA) was used to determine the antibody specificity. The concentration causing 50% inhibition of binding of 3H-tetrahydro-PR toxin to the antibody by unlabeled PR toxin, tetrahydro-PR toxin, PR imine, eremofortin C (EC), acetyl-EC (Ac-EC), eremofortin D (ED) and eremofortin A (EA) were 7, 10, 5, 15, 50, 500 and 800 ng/assay, respectively; for PR alcohol and eremofortin B (EB), the concentration was greater than 10,000 ng/assay. The practical application of using this antibody for RIA of PR toxin was tested by spiking cheese with the toxin. PR toxin was then extracted with ethyl acetate, and analyzed by RIA. The overall recovery for 20 samples with 0.1 to 50 ppm of PR toxin was 93%.

Production and Characterization of Antibody Against 3'-OH-T-2 Toxin.

Antibody raised against T-2 toxin cross-reacted poorly with 3'-OH-T-2 toxin. A new immunogen was prepared by conjugation of hemisuccinate (HS) of 3'-OH-T-2 toxin to bovine serum albumin (BSA). Antibodies against 3'-OH-T-2 toxin were demonstrated by a radioimmunoassay 10 wk after immunization of rabbits with this new immunogen using tritiated 3'-OH-T-2 toxin as the testing ligand. Highest titers (1:6,000) were obtained 17 wk after immunization and two booster injections. The antibodies had good cross-reactivity with T-2 toxin, acetyl-T-2 toxin and 3'-OH-acetyl-T-2 toxin. The relative cross-reactivity of this antibody with 3'-OH-T-2, acetyl-T-2, T-2, 3'-OHacetyl-T-2, 3'-OH-T-2-HS, T-2 isomer, HT-2 and 3'-OH-HT-2 was 1, 3, 4, 5, 15, 30, 45 and 175, respectively. No crossreaction was found when 3'-OH-T-2 triol, T-2-triol, T-2-tetraol, DAS and DON at a concentration of 1 µg per assay was tested. The detection limit for 3'-OH-T-2 toxin by the RIA was about 0.1 ng per assay.