DIRECT ENZYME-LINKED IMMUNOSORBENT ASSAYS FOR THE DETECTION OF THE 8-KETOTRICHOTHECENE MYCOTOXINS DEOXYNIVALENOL, 3-ACETYLDEOXYNIVALENOL, AND 15-ACETYLDEOXYNIVALENOL IN BUFFER SOLUTIONS

Polyclonal antisera against deoxynivalenol (DON) and 3-acetyldeoxynivalenol (3-AcDON) were obtained after rabbits were immunized with human serum albumin conjugates of 3,15-O-dihemisuccinyl-DON and 15-O-hemiglutaryl-3-AcDON, respectively. The specifity and sensitivity of these antisera were tested by using 3,15-O-dihemiglutaryl-DON or 15-O-hemiglutaryl-3-AcDON coupled to horseradish peroxidase as the enzyme-linked toxins in a competitive direct enzyme-linked immunosorbent assay (ELISA). The 50% inhibition level was used for the determination of the cross-reactivities. The anti-DON antiserum showed strong cross-reactivity (relative to DON = 1.0) with 3-AcDON (100.0) and 15-acetyldeoxynivalenol (15-AcDON, 1.1); minor cross-reactions were observed with nivalenol (0.063) and fusarenon X (0.016). The anti-3-AcDON antiserum was most specific for 3-AcDON and had only minor cross-reactions (relative to 3-AcDON = 1.0) with acetyl T-2 (0.025), 15-AcDON (0.016), and T-2 tetrol tetraacetate (0.013). When the antiserum against DON was employed in the direct ELISA, detection limits for DON, 3-AcDON, and 15-AcDON in buffer were 1.0, 0.05, and 1.5 ng/mL, respectively. The detection limit for 3-AcDON in the direct 3-AcDON ELISA was 0.1 ng/mL. After hydrolysis, 3-AcDON gave a response similar to that of DON in the DON ELISA, but levels up to 100 ng/mL were no longer detected by the 3-AcDON ELISA, thus providing a possibility to discriminate between these toxins.