Long-term culture of human trophoblast cells

A technique is presented for the preparation of cultures of replicating human trophoblast cells from term placentas. The adherent cells obtained were very slow growing (doubling time 12.5 days) as measured by the rate of increase in cell protein, [14C]-leucine uptake and cell number. Cells from individual placentas have been maintained in continuous culture for up to 1 year (10-12 passages) and have been successfully recultured after storage in liquid nitrogen. Cultured cells showed positive immunofluorescent staining for human placental lactogen, human chorionic gonadotrophin, transferrin and type IV collagen. The adenine nucleotide content indicated that energetically the cells were in balance even after prolonged culture.