An immunoelectron microscopic study of human placenta using three monoclonal antibodies. 
An immunoelectron microscopic technique was used to analyse the distribution in term human placentae at the ultrastructural level of three antigens recognized by recently developed monoclonal antibodies.  Two of the antigens (recognized by NDOG-1 and NDOG-2) were present only on the outer villous membrane of the syncytiotrophoblast.  The other (HLA-A, B, C) was absent from syncytiotrophoblast and present on some capillary endothelial cells and on Hofbauer cells in the villous stroma.