Abstract: To construct expression vertor of MadCam-1 gene, to expression and purify recombination protein and to prepare polyclonal antibody, which have laid a foundation of studying its function. A pair of primers was designed according to the sequence of MadCam-1 from GenBank. The MadCam-1 gene was amplified by PCR. The expression vector pGEX-4T-1-MadCam-1 was reconstructed and transformed into E.coli BL21,then it was induced by IPTG.The expressed product was identified by SDS-PAGE and Western blotting. Rabbits were immunized with the purified MadCam-1 to generate antisera. The results showed that the homology of 100% of the cloned MadCam-1 gene to that reported in GenBank. The recombinant plasmid pGEX-4T-1-MadCam-1 was constructed successfully. The expression product was identified by Western blotting. The results showed that the molecular weight of recombinant protein pGEX-4T-1-MadCam-1 was 50 ku.Then rabbits were injected with purified protein to induce immunoreactions and the potency of the antibody was as high as 1∶32000. Therefore,the polyclonal antibody of MadCam-1 was induced.The results of this study lay a foundation for further study of the function of dairy cows MadCam-1.

Key words: MadCam-1; cloning; expression; purification; polyclonal antibody