A method described for large scale cultivation ofEntamoeba histolytica axenically in a modified Diamond’s TP-S-1 monophasic medium. Crude amoebaantigen prepared by the ultrasonication of the trophozoites ofE. histolytica, was fractionated by sephadex G-200 column into four different fractions. The whole antigen and its different fractions were freeze-dried and upon reconstitution contained approximately 1.8 mg N/ml or roughly the equivalent of 10 × 10⁶ amoebae per ml. Both whole antigen and its fractions have been used for the detection of specific antibody in the patients’ sera. Rabbits were immunised with the antigen and the immunoglobulins were separated from hyperimmune sera by DEAE-cellulose chromatography and salt fractionations. Sera collected from different categories of amoebiasis patients, amoebic liver abscess, amoebic hepatitis, amoebic dysentery, and asymptomatic amoebiasis, were tested serologically using standard amoeba-antigen for serodiagnosis and epidemiological assay of amoebiasis. Results of the assay showed that standard amoeba-antigen is very useful for diagnosis of invasive amoebiasis.

Fatty acids, cholesterol and glucose present in axenic medium are utilized by growingEntamoeba histolytica but the amoeba is unable to synthesize cholesterol from [U^-14 C^- ] glucose although the label is incorporated into the fatty acids and non-saponifiable fractions of the organism. Exogenously-added sonicated dispersions of cholesterol, Β-sitosterol, lanosterol, lecithin and lauric, palmitic, linoleic and stearic acids are ingested by the amoebae with subsequent loss in amoeboid movement. After a few hours the movement is regained. Cholesterol, lecithin and the fatty acids stimulate amoebic multiplication but are unable to replace serum in the medium either singly or in combination.