Figure 3. A schematic diagram and representative histological image of an osteochondral unit. (A) The zonal structure of the osteochondral unit. (B) Safranin O and fast green staining of a healthy full-thickness osteochondral unit from an adult human. Scale bar: 200 μm. ACAN: aggrecan; Col I: type I collagen; Col II: type II collagen; Col X: type X collagen; Prg4: proteoglycan 4.
