Location of the protein hormones of the placenta by the immunoperoxidase technique.

An attempt has been made to locate human placental lactogen (HPL) and human chorionic gonadotrophin (HCG) in cells within the human term placenta. Using immunoperoxidase techniques on frozen sections of tissue, no difference could be found between specific antisera and control sera. A theory is put forward that it may not be possible to visualize these hormones in the placenta using present immunoperoxidase techniques.