Histological analysis of typical cartilage extracelluar matrix components in native ovine articular cartilage. Hematoxylin & eosin (A) staining shows that chondrocytes of the articular cartilage are irregularly distributed, with insular cells and cells in groups of two to three chondrocytes. Alcian blue (B) staining shows the presence of proteoglycans and an intense staining surrounding the chondrocytes. Type II collagen (C) immune-staining is homogenous and shows presence of the cartilage marker molecule in the pericellular extracellular matrix. Controls (D), incubated with IgG were negative and show specificity of the type II collagen immune-staining.