Identification of cytotrophoblast colonies in cultures of human placental cells using monoclonal antibodies.

The morphological appearance of four distinctive types of colony in human placental cultures is described. Using a panel of monoclonal antibodies, one of these colonies is found to comprise cells with the phenotypic characteristics which allow them to be defined as cytotrophoblast with a reasonable degree of certainty. A second type of colony also contains cells of epithelial origin, but the trophoblast lineage of these cells is more difficult to ascertain. The remaining two types of colony are derived from mesenchymal elements representing either macrophages or fibroblasts. It is hoped that the precise identification of cytotrophoblast colonies will provide a useful yardstick to assess the efficiency of any future techniques which are devised for the selective growth and propagation of human trophoblast in vitro.