Genotypic differences between invasive and non-invasive E. histolytica could explain the 1:10 ratio of symptomatic/asymptomatic infection worldwide. Currently, zymodeme analysis is used to differentiate invasive from non-invasive E. histolytica strains but the technique is cumbersome and expensive. In accordance with the WHO research priorities for amebiasis we report here the further use of an invasive-specific monoclonal antibody against E. histolytica in immunofluorescence, to identify isolates cultured from stool samples of patients from three geographically distant endemic regions: Bangladesh, Colombia and Mexico. We tested 107 E. histolytica isolates and the correlation between zymodeme characterization and the immunofluorescence assay was 100%.