Abstract
Placental alkaline phosphatase was localized in human chorionic gonadotropin producing gestational choriocarcinoma cell-line, designated as GCH-nu, using enzyme cytochemical and immunocytochemical techniques.
Light and electron microscopic observations revealed that the alkaline phosphatase (ALP) specific to placenta was found on the surface of microvilli of the cultured cells. With the enzyme cytochemical method, the heat stable ALP was present on the surfaces of cells which formed mound. While the cells which was spread in-between the mound were negative for the ALP. On the other hand, with the immunocytochemical method, the surfaces of all the cells including those spread between the mound were positive for placental ALP. These observations suggest that all cells possess placental ALP on their surfaces, although those on the surfaces of cells which were spread between the mound were enzymatically inactive but active as an antigen.
