Abstract: Objective To prepare and identify immune serum against the recombinant fusion protein of rhoptry 2 （ROP2） and major surface protein 1（P30） from Toxoplasma gondii. Methods The constructed recombinant plasmid of pET28b/ROP2-P30 was transformed to a bacterium BL21-Codon Plus（DE3）-RIL strain and was expressed under IPTG induction. Cells were lysed by multiple rounds of sonication to obtain supernatant and inclusion body respectively. The inclusion body was washed with 2 mol/L and 4 mol/L urea to remove the nonspecific protein. The washed products diss-olved in 8 mol/L urea were received by SDS-PAGE. Two rabbits were immunized with the fusion protein rROP2-P30 and sera from the rabbits were collected. Immune diffusion test， indirect ELISA and Western-blot were used to detect anti-body titer and specificity of the immune serum against rROP2-P30. Results Immune diffusion test demonstrated that specific immune serum were obtained. Indirect ELISA confirmed that the antibody titer in the serum reached 1:12 800 and the rROP2-P30 was recognized by specific IgG in this serum by Western-blot analysis. Conlusion Specific immune serum against the recombinant fusion protein rROP2-P30 has been prepared.

Key words: Toxoplasma gondii, Recombinant fusion protein, ROP2-P30, Immune serum