We compared multiple strains of lab trophozoites to recent clinical isolates. Clinical isolates were grown in xenic media, and maintained many characteristics of the cyst stage of devlopment Keywords: Stage conversion Overall design: E. histolytica trophozoites of three different strains (HM1:IMSS, Rahman, and 200:NIH) and grown under multiple conditions (Long term axenic growth in TYI, Growth in low glucose media, Mouse adapted parasites and in vivo growth in a mouse model) were compared to recent clinical isolates that had grown in xenic culture for 1-8 weeks.