Abstract: 　Objective To obtain protein of the major surface antigen P30 of Toxoplasma gondii by molecular cloning. Methods The gene of P30
containing the whole P30 gene sequence, without the gene encoding signal peptide was obtained by polymerase chain reaction (PCR) using the primer designed according to the DNA sequence of P30. The recombinant plasmid was constructed using EcoR Ⅰ, Xho Ⅰ and was then transformed into E. coli Top10. The positive clones were identified by restriction enzymes and DNA sequence analysis. The fusion protein was induced by IPTG and purified by affinity chromatography using ProBond~(TM) Resin (a kind of nickel-charged sepharose resin) and was identi- fied by SDS-PAGE and Western blotting. Results The products of PCR, cleavage and link reaction were same as ex- pected and the sequence of inserted fragment in the recombinant plasmid was same as reported except one synonymy muta- tion. A 58 kDa fusion protein was induced by IPTG and was purified by chromatography. Conclusion Fusion protein containing Toxoplasma gondii P30 was achieved and was provided as experiment material for further research.

Key words: Toxoplasma gondii, P30, cloning, purification