Dextran, a hapten carrier in immunoassays for s-triazines. A comparison with ELISAs based on hapten-protein...

A conjugate of 2-aminohexylamino-4-ethylamino-6-isopropylamino-1,3,5-triazine (AHA), a derivative of the herbicide atrazine, with dextran as carrier has been synthesized and used as the coating antigen in ELISA procedures. The quantification of terbutryn, atrazine and prometryn in ELISA formats using monoclonal antibodies and the AHA-dextran conjugate was at least as sensitive as ELISAs using protein conjugates as immobilized antigens (sensitivity at 50% B/B0 was 0.4-0.6 micrograms/l for terbutryn). Formats with immobilized antibody and enzyme labelled AHA proved to be less sensitive (1.5 micrograms/l for terbutryn). The observed differences in sensitivity do not apparently result from structural effects of the carrier bound hapten since all conjugates were prepared with one form of the hapten, 2-aminohexylamino-atrazine, which was covalently linked via its amino function to the carriers or enzymes.