Abstract
The localization of mouse placental lactogen (mPL) in the mouse placenta has been examined with the avidin-biotin-peroxidase complex (ABC) technique. Staining was observed to occur in the basal zone of placentae from days 10, 12, 15, and 18 of gestation. Within the basal zone, the most prominent staining was localized to the cytoplasm of the giant cells. Within the labyrinth, staining was observed in the giant cells in day-15 and day-18 placentae, with a greater number of stained cells being observed in the latter.