Preparation of biotin-labeled polyclonal antibody against Brucella abortus

Objective To prepare and identify the polyclonal antibody against Brucella abortus 544 A. Methods B. abortus544 A strain was resuscitated, cultured and enriched, then inactivated. New Zealand white rabbits were immunized s. c.with the prepared inactivated vaccine on back in several sites for 5 times, of which the heart blood was collected. Sera were separated, from which polyclonal antibody was crudely extracted by salting out with ammonium sulphate and further purified by protein affinity chromatography, then determined for purity by SDS-PAGE, for titer and specificity by indirect ELISA, and for protein content by Bradford method, and labeled with biotin. Results The prepared rabbit polyclonal antibody against B. abortus 544 A showed a high purity and a good specificity, of which the titer was 1 ∶ 256 000, the protein content was 2. 83 mg / ml, and the labeling efficiency was 3. 09 of biotin to antibody. Conclusion Biotinla beled polyclonal antibody against B. abortus 544 A was prepared successfully, which laid a foundation of development of immunological detection kit for B. abortus.