Abstract: ObjectiveTo prepare the actin of Toxoplasma gondii(T.gondii) and the polyclonal antibody against the protein.MethodsActin gene was obtained from cDNA library of T.gondii by PCR amplification and subcloned to vector pET30a.The fusion protein actin-His₆ was expressed in E.coli upon isopropyl-β-D-thiogalactoside(IPTG) induction and then purified with affinity chromatography.The Sprague-Dawley(SD) rats were immunized with actin-His₆ to produce polyclonal antibodies.ResultsThe actin gene was obtained and the recombinant plasmid actin/pET30a was constructed successfully and expressed as a fusion protein.Serum were prepared from rats immunized with actin-His₆ and purified with affinity chromatography to produce polyclonal antibodies with a antibody titer of 1:4000.ConclusionThe protein actin-His₆ was expressed in vitro.Serum and the polyclonal antibody against the protein were prepared,which may provide a foundation for further studies on the invasion mechanism of T.gondii.