[Antigenicity of the human trophoblast]

In this a rabbit immunological serum against human trophoblast was obtained after triple intramuscular superficial villi extract injection from chorion of 6--7 week pregnancy with Freund's adjuvant. In immunofluorescent indirect reaction to this serum made on chorion and placenta sections some most intense specific fluorescence was obtained in cytoplasm of primordial cyto- and synytiotrophoblast. Some favourable influence of antigenic differences between ovum and mother especially implantation has been suggested.