Abstract
Summary E. histolytica has been maintained free of bacteria for 9 days or 3 subcultures in Ringers-Egg-Serum media fortified with the growth factors ribose-5-phosphate, adenosine triphosphate, autoclaved bacterial cells, and diphosphopyridine nucleotide. 2. This method makes available large numbers of amebas (approximately 1 to 1.5 million per ml) free of living bacteria.