Fig. (5) Immunolocalization of type II collagen. Normal menisci (transverse sections of the inner portion of menisci) showed strong immunolocalization of type II collagen (top photos). Type II collagen staining in the surface zone (black arrow) of normal menisci was greater than that in the middle zone (green arrow) and deep zone (red arrow). Type II collagen staining was decreased in OA menisci compared to normal menisci (compare the bottom photos to the top photos). The reduction of type II collagen staining was prominent in all the three zones. Scale bar: 250 µm.