VIABILITY OF HUMAN TROPHOBLAST <i>IN VITRO</i>

Abstract

Summary Human placental monolayer cultures contain three main cell types: epithelioid, giant multinucleated and fibroblastic cells. Only epithelioid and giant multinucleated cells are of trophoblastic origin. The viability and relative abundance of the three cell types were investigated using four methods of assessment: trypan blue exclusion, phase‐contrast microscopy, mitotic indices and synthesis of human chorionic gonadotrophin. Between days 1 and 8, epithelioid and giant multinucleated cells were dominant. The mitotic index gradually declined during this period but cell viability as assessed by dye exclusion and phase‐contrast microscopy was high and active synthesis of chorionic gonadotrophin occurred. Fibroblastic cells dominated the culture from approximately day 9. Experiments with trophoblast in vitro should therefore be performed during the first eight days of culture.