Abstract:

As one of β-agonists, ractopamine has been prohibited in food production and animal husbandry. To enforce regulation, it is necessary to develop a rapid detection system to measure the residue of ractopamine in animal food production. In this study, a new ractopamine immunogen was synthesized by using 4-aminobenzoic acid as a linker to connect hapten with carrier protein, bovine serum albumin (BSA). Besides the immunogen, a new ractopamine coating antigen was synthesized also by using 1,4-butanediol diglycidyl ether (BDE) as a linker to connect ovalbumin (OVA). The BSA conjugate was used to immunize New Zealand rabbits and polyclonal antibodies against ractopamine were obtained. The titers of antibodies were up to 102400 by indirect ELISA and the antibodies showed high sensitivity in the heterologous assay using RAC-BDE-cOVA as coating antigen, with an IC50 value of 4.34 ng/ml. The artificial antigen has perfect immunogencity and the obtained antibody has excellent sensitivity.

Key words: ractopamine, ELISA, conjugation, antigen