Preparation of anti-ractopamine polyclonal antibodies

Ractopamine HCl was activated by the multi-anhydride method and the activated(ractopa-)mine was conjugated to a carrier protein by the mixed-anhydride method.The carrier protein was keyhole limpet hemocyanin(KLH) and bovine serum albumin(BSA).The KLH conjugate(KLH-Rac) was used as immunogen and the BSA conjugate(BSA-Rac) was used as the coating antigen for the development of an ELISA.New Zealand rabbits were immunized with KLH-Rac.Titer of the polyclonal antiserum detected by the developed indirect ELISA method was more than 6,000.The antiserum IC_(50) detected by an indirect competitive ELISA was approximately 5 ng/mL.The cross reactivity with clenbuterol,salbutamol and terbutaline was less then 0.01%.