Table 1.

Details of the immunohistochemistry methodology employed

Target	Antigen retrieval	Blocking step and primary antibody	Secondary antibody
Aggrecan	0.1% w/v hyaluronidase in Tris-buffered saline (Sigma, Poole, UK), 30 minutes at 37°C	20% v/v rabbit serum, and mouse monoclonal aggrecan 1° (1:25 dilution; AbCam, Cambridge, UK)	Biotinylated rabbit anti-mouse antiserum (1:400; Dako, Ely, Cambridgeshire, UK)
Sox-9	None required	20% v/v swine serum, and rabbit polyclonal Sox-9 1° (1:100 dilution; SantaCruz, Heidelburg, Germany)	Biotinylated swine anti-rabbit antiserum (1:400; SantaCruz)
Type I collagen	0.01% hyaluronidase (Sigma), 0.02% trypsin (Sigma) w/v in Tris-buffered saline	20% v/v rabbit serum, and mouse monoclonal type I collagen 1° (1:250 dilution; ICN, Basingstoke, UK),	Biotinylated rabbit anti-mouse antiserum (1:400; Dako)
Type II collagen	0.1% w/v hyaluronidase in Tris-buffered saline (Sigma), 30 minutes at 37°C	20% v/v rabbit serum, and mouse monoclonal type II collagen 1° (1:100 dilution; MP Biomedicals, Illkirch, France)	Biotinylated rabbit anti-mouse antiserum (1:400; Dako)
Type X collagen	1 mg/ml hyaluronidase, 0.25 U/ml chondrotinase in Tris-buffered saline, 1 hour at 37°C; followed by 0.1% protease in Tris-buffered saline, 10 minutes at 37°C	25% v/v goat serum, and mouse monoclonal type X collagen 1° (1:200 dilution; AbCam)	Biotinylated goat anti-mouse antiserum (1:100; SantaCruz)
Caspase 3	None required	20% v/v donkey serum, and goat polyclonal caspase 3 1° (1:500 dilution; SantaCruz)	Biotinylated donkey anti-goat antiserum (1:300; SantaCruz)