Figure 2

Localization of Sulf-1 and Sulf-2 in normal cartilage. Representative sections of 26-year-old (a, d) and 74-year-old (g) normal cartilage (Mankin scores: 0 and 2) as seen on safranin O staining are shown (n = 8; 19 to 37 years old). Sulf-positive cells (brown staining) are present in the superficial zone and the top of the middle zone, and Sulf-2 expression is greater than Sulf-1 (b, c, e, f, h, i) in both young and old cartilage. Magnifications: ×10 (a-c) and ×40 (d-i).