Improved molecular karyotype of Entamoeba histolytica.

Different electrophoretic conditions were used to improve the molecular karyotype of Entamoeba histolytica clone L6 derived from the heterogeneous strain HM1:IMSS. Eleven to 17 bands ranging between 0.3 and over 3 megabases (Mb) were resolved by transverse alternating field electrophoresis (TAFE). Amebic chromosomes presented similar pattern when they were TAFE separated at 72, 90 or 120 h running time, but resolution of the bands was increased at 90 h, and the best electrophoretic pattern was obtained at 120 h. Bal 31 digestion of DNA in the plugs suggested that most of the bands are lineal molecules and that pMD, an amebic DNA fragment, hybridizes with both lineal and nonlineal DNA molecules.