Figure 4: Photomicrographs of control group of human placenta depicting a) faintly positive PAS stain in the villous core and basement membrane of the trophoblasts. Cytotrophoblast cells seen within the villous stroma. Syncytial lining is present at places. Syncytial knots are plenty (10x). b) A higher magnification of previous micrograph (40x).Inset