RESUMO
Objective To investigate the diagnostic value of the recombinant surface antigen 1 (rSAG1) in immunodiagnosis of toxoplasmosis. Methods Isopropyl β-D- 1 -thio-galaetopyranoside (IPTG) was used to induce the expression of recombinant plasmid pET28a-SAG1 of Escherich coli(pET28a-SAG1/BL21 ). The expression products (rSAG1) of pET28a-SAG1/BL21 were identified by Western blotting. The serum of mice infected with Toxoplasma gondii tachyzoites, normal mouse serum and the serum from 10 toxoplasma gondii patients were used as primary anti-Toxoplasma gondii antibodies, and the rSAG1 gene products were identified by Western blotting, by which the diagnostic value of rSAG1 in Toxoplasmosis was compared. Results After induction and purification, rSAG1 protein was obtained and its relative molecular mass was 38.5 × 103. The fusion protein could be recognized by the serum of mouse infected with Toxoplasma gondii tachyzoites, rSAG1 of expression products of surface membrane antigen SAG1 gene from Toxoplasma Gondii could be detected in 4 cases from 10 patients by Westem blotting.Conclusion The rSAG1 has a potential value in the immunodiagnosis of Toxoplasmosis.