Detection and Characterization of Blood Group Antigens on Untransformed Human Amnion Cells

Amnion cells, primary and in culture, along with the infant's own erythrocytes, were tested by mixed agglutination for blood groups A, B, H, M, N, Tj^a, Rh_o(D), Yt^a, I and i. Studies were carried out on cell cultures ranging in age from one day to 39 days. Only A, B, H, Tj^a, I and i could be demonstrated on amnion cells. Decrease in the number of cells positive for Tj^a, and possibly for A and B, was observed in the course of cell passages. In cultures positive for H, the percentage of positive cells, although small, generally continued as long as the culture was studied.