IMPROVED METHOD FOR THE CONCENTRATION AND PURIFICATION OF FECAL CYSTSOF ENTAMOEBA-HISTOLYTICA FOR USE AS ANTIGEN

Human stool samples are the most widely used source of E. histolytica cysts for diagnosis and research. Cysts concentrated from faecal sampl es are contaminated with faecal debris and bacteria and are unsuitable for use as antigens. Other gradient purification and sedimentation pr ocedures result in considerable cyst losses. We present an effective a nd simple purification procedure using varying densities of Percoll th at yields an adequate cyst concentration from a moderate cyst load in a single stool sample.