Immunocytochemical detection of Entamoeba histolytica

Human anti-Entamoeba histolytica immunoglobulin was used to detect Entamoeba histolytica in 74 positive samples from several different sources, using an indirect immunoperoxidase method. In 73 samples, the protozoan was easily identified. Trophozoites and cysts of all cultured Entamoeba strains examined were strongly stained, and as few as 3 trophozoites per microscope slide could be detected. In addition, 51 negative control samples were also tested and non-specific reactions were not observed. These preliminary results show that this method is both sensitive and specific, and can easily detect trophozoites and cysts of different E. histolytica strains.