Objective: To prepare recombinant human monoclonal antibody Fab fragments specific to the surface antigen of Entamoeba histolytica.
Methods: Total RNA was isolated from lymphocytes which were separated from an asymptomatic E. histolytica cyst carrier. The genes of IgG light chain and Fd region of heavy chain were amplified by a reverse transcriptase PCR and ligated with a plasmid vector. After the genes were introduced into Escherichia coli, the clones expressing Fab fragments specific to the surface antigen of E. histolytica were screened and the product was purified.
Results: Thirty thousand clones were screened and one of them was proved positive to the surface antigen of E. histolytica.
Conclusion: This study demonstrated that the bacterial system can be used to produce recombinant human monoclonal antibody Fab fragments specific to the surface antigen of E. histolytica and they may be applicable for the future diagnosis and treatment of the infection.