The heat lability of the growth promoting ability of the CLG and S-F media for the propagation of Entamoeba histolytica has been studied.
The supernatant fluids used in these media were subjected to heat in a water bath. The critical temperature on heating for 15 minutes for the CLG medium appears to be 55°C and for the S-F medium 53°C.
Enhanced propagation of E. histolytica was observed after 24 hours and sometimes after 48 hours in these heated supernatant fluids. It is suggested that this results either from the release of a stimulatory substance or the destruction of an inhibitory one by heat. Evidence indicates that this is different from the heat labile factor necessary for continued propagation.